第 90 期·中文精讀

德米特里·科爾金:冠狀病毒的計算生物學

Dmitry Korkin: Computational Biology of Coronavirus

計算生物學家講解如何用建模與資料分析研究新冠病毒的結構、傳播機制與潛在藥物靶點。

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一個直徑百奈米量級的小東西,比蝴蝶扇一下翅膀帶起的氣流還小得多。它沒有大腦,沒有新陳代謝,嚴格說都算不上活著。但它能讓全球股市熔斷,讓幾十億人困在家裡,讓一整個國家的經濟按下暫停鍵。

德米特里·科爾金(Dmitry Korkin)是伍斯特理工學院(WPI)的生物資訊學與計算生物學教授,研究複雜疾病的生物資訊學、計算基因組學和生物醫學資料分析。今年二月,他的團隊用新冠病毒的基因組序列,重建了它主要病毒蛋白的三維結構,以及這些蛋白與人體蛋白的相互作用,等於給這個病毒畫了一張結構基因組圖譜,並且把資料全部公開。

這次對話發生在疫情最緊張的時候。他們聊了病毒本身,聊了計算手段怎麼幫我們理解結構、進而設計抗病毒藥物和疫苗,也聊了病毒為什麼讓人著迷,甚至有點"聰明"。

病毒是機器,不是生命

科爾金一開口就把病毒定義得很乾脆。

"它不是一個活的有機體,它是一臺機器。而且是一臺被打磨到極致的機器,功能數量有限,但它只需要剛好夠用的資訊就能完成這些功能,還帶著自我修改的能力。"(德米特里·科爾金)

把病毒叫機器,聽起來像是低估了它。但科爾金覺得恰恰相反。他說的"智慧"不是人類那種智慧,也不是人工智慧那種智慧。

"病毒的智慧在於它的簡單,用極少的材料和資訊做成了極多的事。"(德米特里·科爾金)

他甚至懷疑病毒是群體智慧最基礎的樣本。單個病毒沒什麼,當成千上萬個病毒作為一個整體行動時,效率高得嚇人。

那病毒到底算不算生命?科爾金說不算,理由是它不自主。它缺少關鍵工具,必須寄生到宿主細胞裡,借用對方的核糖體來列印自己的蛋白質。病毒連"印表機"都沒有,只能借別人的用。

這裡我故意抬槓:人類也需要地球這個宿主才能活。按這個邏輯,人類也不自主。

科爾金的回應很坦白。他說這確實是很難回答的問題,說到底是個定義問題。他傾向於用"是否自主"這條線來區分生命和機器,僅此而已。

越致命,越難傳播

說到傳播力,繞不開一個數字:R0,也就是一個感染者平均能傳染給多少人。

新冠的估計在 1.5 到 3 之間。天花是 5 到 7。麻疹超過 15。流感遠低於這些數字。

科爾金說,這裡有個耐人尋味的規律:看起來病毒越致命,傳播力反而越弱。MERS 的死亡率在兩三成以上,但它從來沒變成大流行。幾年前在中國出現的 H7N9 禽流感,死亡率超過 30%,但它主要從鳥傳人,人傳人的能力很弱。

為什麼高致命性和高傳播力很難兼得?科爾金說他也沒有答案,這仍然是個開放問題。

換句話說,那些把我們折騰得最慘的病毒,其實並沒有想要把我們殺死。宿主死了,病毒自己也走不遠。這是一場漫長的談判,雙方都在找那個能長期共存的平衡點。

聊到這裡,我問了個稍微嚇人的問題:未來一百年,更該擔心自然出現的病毒,還是被人為改造出來的病毒?

科爾金說他更擔心天然的。因為新毒株一直在冒出來,這是自然過程,而這個過程本身就已經足夠強大。他讀過不少關於現代生物技術改造病毒的論文,也希望這不會在不久的將來成為主要威脅。

但他補了一句很有意思的話:改造病毒有一個和核武器一樣的問題,它很難不導致相互毀滅。你沒法控制一個能當武器用的病毒。

一半感染者沒有症狀,這才是真正的變數

病毒怎麼傳播,牽扯的因素很多。有生物層面的,也有社會層面的。病毒能在物體表面存活多久,複製速度多快,這些都好理解。

科爾金點出一個過去大家不太在意、這次卻至關重要的因素:無症狀感染者的比例。

冰島做過一項規模很大的篩查,結果是大約 50% 的感染者無症狀。這些人自己不知道,卻照樣在傳播病毒。

他提了一個對比:豬流感當年感染的人數以十億計,占人口的 20% 到 30%。幸運的是致死率低。但一個病毒能這麼快席捲整個人群,本身就夠嚇人的。

"這大概是我最喜歡的蝴蝶效應的例子,因為它比蝴蝶還小。病毒的大小隻是幾個原子,幾個原子的改變,就造成了這麼大的影響。"(德米特里·科爾金)

那第一下扇動的翅膀是什麼?是讓病毒能從蝙蝠跳到人身上的那幾處突變。科學家到現在還在找"零號病人",還在弄清到底是什麼樣的基因改變,讓這個原本待在蝙蝠體內的東西,先學會了跨物種,又學會了人傳人。

科爾金提到,幾年前有科學家用實驗證明,只要改動流感病毒上的幾個殘基,就能讓它跨物種傳播。這項研究當時引發巨大爭議,甚至一度被叫停,後來還是發表了。

爭議的點很直接:你公開演示了怎麼改造,是不是等於給了別人說明書?科爾金的立場是,這類研究應該做,人類需要被充分告知,需要儘可能理解機制,才能預防。所有答案最終都會指向更好的疫苗,甚至通用疫苗。

什麼是通用疫苗?他舉了流感的例子。每年打流感疫苗,是因為我們在和不斷變異的病毒打軍備競賽。如果下一次流感大流行來了,現有疫苗大機率救不了我們,因為毒株可能完全不同。如果能設計出一種對甲型流感所有毒株都有效的疫苗,不管它從哪個物種跳過來,那會是科學的一次巨大勝利。

二十九個蛋白,我們至今沒搞清它們幹什麼

回到病毒本身。它怎麼進入人體?科爾金拆成了幾個關鍵步驟。

第一步是附著。新冠病毒和 SARS 走的是同一條路:病毒表面的刺突蛋白(spike protein)抓住人體細胞上的 ACE2 受體。

而且有越來越多的證據顯示,新冠病毒結合這個受體的效率,比 SARS 還要高。

刺突蛋白不是單獨行動的。它會三份複製湊在一起,形成三聚體,作為一個功能單元去和 ACE2 對接。這就是為什麼你在所有病毒示意圖上看到的那一圈"皇冠"。

第二步是進入。病毒把自己的膜和宿主細胞的膜融合,把 RNA 釋放進去,然後劫持細胞的機器。

病毒的結構其實很簡潔。表面有三類主要蛋白:刺突蛋白、數量最多的膜蛋白(membrane protein,負責撐出包膜的形狀和曲率)、還有數量很少的包膜蛋白(envelope protein)。包膜蛋白到底幹什麼,至今還在研究中。

裡面還有一個核衣殼蛋白(nucleocapsid protein),作用是包住病毒 RNA,形成一個保護殼。

然後是一個讓人意外的數字:流感病毒只有八九個蛋白,新冠病毒至少有 29 個。

科爾金說,儘管人類研究冠狀病毒已經二十多年,這 29 個蛋白裡還有很多功能沒被完全搞清楚。

怎麼搞清楚?這就是計算生物學能插手的地方。過去幾十年,科學界積累了海量關於各種病毒蛋白的知識。拿到一個新病毒的基因組,先識別出可能的基因和蛋白,再去和已知的蛋白做比對。如果相似,就能推斷功能。蛋白酶、聚合酶這類關鍵部件,往往一眼就能認出來。

麻煩的是那些真正全新的蛋白。沒有參照物,只能從零開始,難度陡增。

科爾金強調,他們做出來的所有預測都必須回到實驗裡驗證。生物資訊學的角色,是幫實驗科學家把發現過程加速,而不是替代實驗。這個鏈條通常是這樣:做計算的人給預測,病毒學家做驗證,分子成像專家用電子顯微鏡看結構,生物化學家和藥企的人再往下接。

從一個字母串,到一個三維結構

那篇論文叫《SARS-CoV-2 的結構基因組學揭示病毒蛋白中進化保守的功能區域》。名字很長,做的事情可以講得簡單。

新冠病毒的基因組是一串不到三萬個核苷酸的序列,本質就是一串字母。這串字母本身沒什麼用,得先確定基因的邊界,才能知道它對應哪些蛋白。

有了蛋白序列,下一步就是找三維結構。這裡用的方法叫同源建模,或者叫模板建模。核心假設是:兩條序列如果字母上相似,結構大機率也相似。

這個方法有好處也有代價。代價是,你可能拿不到全部 29 個蛋白的模板。好處是,只要有模板,建模的精度就非常高,遠高於那些不用任何模板的方法。

拿到單個蛋白的結構之後,還要看它們會不會互相結合。有些蛋白自己就能湊成多聚體。刺突蛋白要三份,包膜蛋白要五份,形成一個五聚體環。

科爾金說,判斷蛋白會不會相互作用,有兩個思路。一是看以前解出來的複合物結構,二是從已知的相互作用資料裡推斷。他們手上既有結構資訊,也有從 MERS 和其他相關病毒那裡積累的相互作用知識。

這裡有個漂亮的洞察:相互作用是結構問題,但結構本身又在執行功能。一個蛋白之所以要和另一個結合,往往是因為某個功能必須靠這個組合才能完成。所以你從結構入手,最後會繞回到功能上。

論文裡有一張圖,把病毒蛋白按結構畫成一堆藍色、青色的塊,再把和近親病毒不同的部分標成粉色。

粉色的部分很有意思。在二維序列上看,這些差異可能離得很遠,互不相關。但一放到三維結構裡,它們常常聚在一起。

這說明什麼?這些差異並非隨機漂變,它們很可能指向功能位點。某個區域高度突變,可能是因為那裡正在和別的分子打交道,進化的壓力集中在那裡。

再看整體模式:新冠病毒裡有些蛋白幾乎原封不動,和 SARS、和蝙蝠冠狀病毒一模一樣,另一些則突變嚴重。進化並沒有均勻地掃過整個基因組,它精準地挑了幾個目標下手。

這篇論文的起點,是一場被忽視的本地疫情

故事要倒回到 2019 年 9 月。

那時候新英格蘭地區爆發了另一種危險的病毒:東部馬腦炎病毒(Eastern Equine Encephalitis,簡稱 Triple E)。這個病毒攻擊大腦,有死亡病例,主要傳播媒介是蚊子。

當地經濟受了影響,學校六點以後關閉,孩子們不許在外面活動,因為兒童感染後的後果特別嚴重。疫情一路蔓延到新罕布什爾和康涅狄格。

科爾金在 WPI 教生物資訊學,那是個很強調"用真實問題學習"的地方。他想,這正好是個完美的案例研究。

Triple E 有個尷尬的處境:它是個"被忽視的疾病"。規模不夠大,藥企不會為它專門開發抗病毒藥,國家基金也不容易批下來。但這不代表我們什麼都做不了。

於是他設計了一個專案,用生物資訊學去儘可能理解這個病毒:它的蛋白結構是什麼樣,蛋白之間怎麼相互作用,怎麼和宿主蛋白相互作用,它是怎麼進化的,接下來可能往哪走。

專案在十二月中旬做完,參與的都是本科生,本來要寫成一篇文章,學生都是共同作者。

幾周後,他聽說了中國報告的一種神秘新病毒。他第一反應是:我們剛做過這件事,為什麼不對這個新病毒再做一遍?

然後就是等基因組公佈。因為基因組序列是第一步,沒有它什麼都做不了。

第一版預印本他們甚至沒發到 bioRxiv,因為當時那個平臺已經被投稿淹沒,光是透過初審掛上網就要五六天。他們乾脆把預印本放在自己網站上,很快就有人來看。

科爾金說,這件事讓他重新理解了學術出版。知識本身正在變成核心價值,而不是承載知識的論文或期刊。加速的審稿流程、鋪天蓋地的預印本,正在從根本上改變我們對"論文"這個東西的理解。

老藥能不能治新病,答案藏在結合位點裡

他們的研究裡最有價值的一條發現是:病毒表面那些被已知小分子藥物靶向的結合位點,幾乎沒怎麼變。

這意味著什麼?意味著原來針對 SARS、針對 MERS 開發的藥物分子,很可能對新冠病毒同樣有效。

反過來,他們也標出了哪些部分已經變了,哪些部分還保持原樣。等於給藥物研發劃出了重點區域。

當然,所有預測都還要實驗驗證。但至少方向清楚了。

聊到具體藥物,科爾金點了瑞德西韋(Remdesivir)。它原本是為埃博拉和馬爾堡病毒開發的,後來被證明對 SARS 有效。它的原理是模仿 RNA 裡的一種核苷酸,從而阻斷病毒複製。

還有一類藥專門抑制蛋白酶,也就是那個負責"剪開"蛋白序列的東西。另有一種原本是為瘧疾開發的藥物,也在候選名單裡。

這裡就是計算生物學真正發揮作用的介面。我們手上可能有一個對 SARS 和 MERS 都有效的完美候選藥,但它對新冠病毒有沒有效,沒人知道。 影響藥效的因素很多,最直接的一條是:如果結合位點突變了,藥物就貼不上去了。科爾金團隊的工作,正是去看這個位點有沒有變。目前看,他們檢查的那幾個配體結合位點基本完好。

我問了個更現實的問題:抗病毒藥物和社交距離,哪個才是短期內的答案?

科爾金的判斷是抗病毒藥物。他注意到新聞裡越來越多醫院開始給病人用新的候選藥。經濟要重啟,我們確實需要它。但他也說,自己沒法預測經濟重啟會怎麼走,因為我們已經陷得太深,而且不只是美國,是全球性的。第二波的可能性始終存在,所以必須非常小心,必須遵守醫生給的所有防護建議。

病毒會不會變異到讓抗病毒藥失效?他說不知道,這正是需要研究的東西。

"這是個美麗又可怕的過程,病毒可能變異,繞開我們擺在它面前的東西。"(德米特里·科爾金)

這個機制沒什麼神秘的,就是進化。病毒身上沒有被刻進任何東西,它只是在和宿主一起進化。科爾金說,這是進化論最乾淨的樣本之一。病毒之所以能這麼簡單,恰恰是因為它把大部分必需功能都外包給了宿主。外包得越多,自己需要背的包袱就越少。

不過最近科學家發現了和細菌一樣大的病毒,巨型病毒。這些發現讓學界重新思考病毒的起源,以及到底是什麼進化機製造出了病毒這種東西。

摺疊一個蛋白質,比下圍棋難多了

蛋白質是一條氨基酸鏈,也就是一串殘基,然後它會自己摺疊成奇形怪狀的三維結構。這個摺疊過程怎麼發生的,是個懸賞百萬美元級別的難題。

詭異的地方在於:你用高溫把它解開,它冷卻後往往又會折回原來的形狀。我們大致知道摺疊的機制,但把所有機制拼起來算清楚,計算量極其龐大。

那蛋白質會折成任意多種形狀嗎?科爾金說,通常認為每個蛋白有一個標準構象,但也有很多情況下,蛋白在去穩定化之後會折成另一種構象,尤其是那些由多個結構單元組成的蛋白。

這些結構單元叫蛋白結構域(domain)。一個結構域通常進化上保守,單獨執行一個功能,有自己清晰的三維摺疊方式。人體細胞裡一個平均蛋白,大概有兩三個這樣的結構域,它們先各自摺疊,再拼成更大的三維結構。

目前的進展是:200 個殘基以內的小蛋白,我們折得還不錯。大蛋白還差得遠。 跨膜蛋白尤其難,偏偏它們又極其重要。

這是個組合爆炸問題,但也不是隻能硬算。機器學習的方法正在進入這個領域。

聊到 Foldit 這個遊戲,科爾金笑了。他當博士後那會兒就接觸過,覺得它設計得很透明、很直觀。後來有篇頂級期刊的論文,共同作者就是這遊戲的玩家,他們解出的結構比科學家自己算出來的還好。

這件事的意義很大。那些對計算機來說極其困難的問題,人類大腦卻未必覺得那麼難。 存在性證明一旦出現,方向就開啟了。

那蛋白質摺疊到底是可學習的問題,還是暴力計算的問題?我們是在深藍下棋的年代,還是在 AlphaGo 下棋的年代?

科爾金說,正在往後者走。這個領域有個奧運會,叫 CASP,各團隊拿到同樣的蛋白序列,比賽誰能預測準結構。最近一屆比賽裡,AlphaFold 是最頂尖的隊伍之一,如果不是最頂尖的那個。

過去幾十年積累的結構資料,終於到了能被總結、被泛化、被用來預測新結構的階段。

而這一切的前提,是蛋白質資料庫(Protein Data Bank)這樣的開放資料。科爾金說,這個資料庫最早的版本還是記在卡片上的。每解出一個蛋白或蛋白複合物,就提交進去,所有人共享。這裡沒有囤積發現的習慣。

他覺得這場疫情恰好證明了科學界協作的能力。人們建立新合作的速度、互相提供幫助的意願,都上了一個新臺階。

給病毒粒子建模,順便設計疫苗

他們的下一步,是把單個蛋白拼成一個完整的病毒粒子模型。

一個病毒粒子的表面是一層脂雙層包膜,上面嵌著蛋白。基於顯微影象推測,它表面大約有 50 到 100 個刺突蛋白,200 到 400 個膜蛋白二聚體,膜蛋白排列成整齊的晶格,像一層地毯。偶爾還能看到包膜蛋白組成的五聚體環。

這裡有個有意思的細節。網上流傳的病毒示意圖,大多是完美的球形,上面插滿尖刺。但真實的顯微照片沒那麼規整。他們在德州農工大學的合作者 Benjamin Newman 最近發表的工作提出並給出了一些證據:病毒粒子的真實形態是拉長的橢球,而非球體。科爾金團隊正把這個結論納入自己的模型。

為什麼要在意形狀?因為這直接關係到疫苗和奈米顆粒的設計。

疫苗的原理,是訓練免疫系統認識這個新威脅,讓它產生能結合刺突蛋白的抗體。抗體一旦貼在刺突上,刺突就沒法再抓 ACE2 受體,病毒也就進不去細胞了。

那奈米顆粒設計是什麼?就是人工造一個模仿病毒粒子的東西。它甚至可能去和真正的病毒粒子競爭,從而減輕感染。

現有的疫苗路線有好幾種。一種是把病毒在細胞培養裡反覆傳代,讓它適應胚胎細胞,從而對人細胞的相容性下降。這樣的病毒顆粒還在,但效率低,複製慢,打進人體後免疫系統能認識它,人最多隻有輕微症狀。另一種是隻取病毒的無功能部分,或者去掉遺傳物質,讓它根本無法複製。

設計疫苗最大的障礙是什麼?是基礎理解不夠,還是實驗驗證和審批流程太慢?科爾金說兩者都是。對分子機制理解得越深,疫苗設計就能越高效。但疫苗終究要測試。

18 個月的時間表,在歷史上看已經是極度的加速。科爾金說他記得讀過一些老疫苗的故事,從設計到充分測試、再到量產,可能要花上十年。

郵輪上的殭屍末日:把病毒寫成一個智慧體

科爾金還做流行病學建模,具體說是基於智慧體的模擬(agent-based simulation)。

這裡有個時間上的巧合。這個專案做了五年,跨年夜他收到學生郵件,說最後一組實驗完成了。三週之後,就出了"鑽石公主號"的事。

這個專案的代號,是幾個本科生起的,叫"郵輪上的殭屍末日"。

為什麼是郵輪?因為郵輪上最常見的病毒是諾如病毒,就是那種腸胃型流感。它經常造成整船人上吐下瀉,嚴重時郵輪得取消航程、原路返航。傳染病爆發一直是郵輪經濟最大的威脅之一。

傳統流行病學研究尺度很大,他們想研究的是一種封閉環境裡的小尺度傳播。郵輪可以,學校可以,大公司也可以,凡是人們密集互動的地方都行。

這種模型的好處是能實時追蹤全過程,能看到感染者和病原體之間互動的完整演變。

他們做了一件以前沒人做過的事:把病原體本身也做成一個智慧體。

通常在這類模擬裡,智慧體代表單個的人,用接觸圖來表示人與人之間的互動。科爾金他們把病毒也寫成一個獨立執行的智慧體,這樣就能同時建模宿主一側和病原體一側的行為。

好處是模型變得非常靈活,可以把所有關鍵引數都塞進去:病毒怎麼在宿主之間傳播,在物體表面能存活多久,無症狀和有症狀時分別排出多少病毒顆粒。全部可以編碼進去。

他們從諾如病毒和殭屍開始,接著模擬了埃博拉、流感、SARS。為了給學生加點刺激,他們還模擬了電影《傳染病》裡的那個病毒。

那部電影的科學顧問是哥倫比亞大學的病毒學家 Ian Lipkin,病毒是他基於尼帕病毒設計的,又混進了 SARS 和流感這類空氣傳播病毒的想法。有意思的是,電影裡給的細節足夠多,多到他們真的能把那個虛構病毒建模出來。

科爾金還講了個細節:電影裡從檢測出病毒到科學家看清表面蛋白結構,大概只過了一週。他跟學生說,你要是問實驗生物學家,他們會告訴你這不可能,解一個晶體結構要幾個月甚至幾年。但你要是問生物資訊學家,他們會說,做個同源建模不就完了。電影裡甚至出現了進化樹,把那個病毒和其他病毒的關係畫了出來。這部電影在科學上花的心思相當多。

那這類模擬真能預測未來嗎?還是隻能用來比較不同干預手段的相對效果?

科爾金說兩者都有。從新冠病毒身上,我們正在學到的是,現有的干預手段可能不夠有效。而一個被過去幾次大流行忽視的關鍵因素,就是無症狀期的影響。這個病毒的無症狀期特別長,這直接把防控變成了一場全新的遊戲。

無症狀的人傳染性有多強?一個重要的引數是看他們排出多少病毒顆粒隨時間變化。已有的研究顯示,人在出現症狀之前就已經具備傳染性,排出的病毒量足以感染下一個宿主。

他提到有研究說,在 14 天的觀察週期裡,第一週往往是傳染性最強的時候。不過他也說,還在等更大樣本、更可靠的資料。

他還提到一個很新的結論:康復後大概有一段時間是查不到病毒排出的,也就是不傳染。

口罩、信任,和一場巨大的心理學實驗

口罩有沒有用,爭論一直很激烈。科爾金的觀點很樸素:口罩兩個方向都起作用,既擋住飛進來的病毒顆粒,也讓潛在的傳染者不去散播病毒,尤其是那些自己都不知道自己感染的人。

既然至少 30% 的無症狀感染者完全沒有症狀,不咳嗽、不發燒,卻照樣排出病毒,口罩的意義就清楚了。

我提到自己戴著口罩去超市被人側目,那是一週前的事。科爾金說情況應該已經變了,CDC 也開始建議戴口罩。

他翻過西班牙流感時期的老照片,那時候幾乎所有人都戴口罩。有一張標誌性的照片,舊金山一輛電車上,售票員拒絕讓沒戴口罩的人上車。

他說,這背後其實是個態度問題:我們有多害怕,我們有多認真對待這件事。他的判斷是,應該認真,因為這件事確實非常嚴重。

但我從心理學角度有個擔憂。口罩會遮住面部表情,讓人與人之間產生距離感。同時它又在傳遞一個訊號:我在乎你的健康。這個權衡很有意思。

科爾金接了一句:我們已經在物理上保持距離了。等經濟重啟、大家重新靠近的時候,那會是一段重建信任的漫長過程,而不是讓所有人都變成重度潔癖。

俄羅斯、口音和那一排搖頭娃娃

科爾金有很重的俄語口音。他 1999 年先去了加拿大,再去了美國,那時候他 22 歲。他說,那年頭帶上的口音,就跟了他一輩子。

蘇聯解體時他還是個孩子,但已經能感覺到變化在發生。

他小時候最想當的是客機飛行員,為此還準備去讀相關的大學。但他一直對科學著迷,不只是數學,還有生物、化學、物理,四個學科他都喜歡。後來他發現自己最大的熱情在數學,在莫斯科國立大學讀書時,他意識到自己想把數學知識和真實問題結合起來。

那時候有個很流行的領域叫控制論,嚴格說不算電腦科學,更像是計算機器人學,他特別想做這個。

我問了個有點冒犯的問題:在俄羅斯做開放的大科學、搞協作,是不是很難?

科爾金說他很幸運,在數學和生物資訊學上都有俄羅斯的合作者。莫斯科、新西伯利亞、聖彼得堡、喀山,都有很強的團隊,也有很棒的想法,對合作很開放。他說自己沒遇到過建立合作上的困難。

但我也說了自己的觀察:搞人工智慧的人,法國張開雙臂歡迎,俄羅斯這邊我感受不到那種熱情。俄羅斯有人,有朋友,有有趣的靈魂,但科學共同體層面,沒有大型會議,沒有那種擁抱。

科爾金想了一下,說他確實想不起來俄羅斯有什麼大型 AI 會議。

他也提到自己回俄羅斯很麻煩。他現在是美國公民,回去的手續很複雜,不是個輕鬆的過程。他希望眼下的特殊局面能推動遠端協作,因為計算科學家其實完全可以遠端工作。當然,實驗科學家這段時間會非常難。

聊到輕鬆的話題,科爾金辦公室裡有一整排科學家搖頭娃娃。他本來想帶過來,但娃娃們正在他辦公室裡保持社交距離,彼此隔得很開。

他收集這些娃娃有十二三年了。第一對是沃森和克里克。而最新的一個,也是他最喜歡的一個,是羅莎琳德·富蘭克林(Rosalind Franklin)。拿到她的時候他特別高興。

他手上的名單還包括牛頓、愛因斯坦、居里夫人、特斯拉、達爾文。

還想添誰?他說想加柯爾莫哥洛夫(Kolmogorov)。他敬佩柯爾莫哥洛夫對科學的投入,也敬佩他對教育的投入。柯爾莫哥洛夫在莫斯科創辦了一所學校,科爾金上學的那所高中就是以他命名的。

還想加圖靈和馮·諾依曼,他一直奇怪為什麼沒人做圖靈的娃娃。還有萊納斯·鮑林(Linus Pauling),他心目中一位最偉大的化學家,發現蛋白質二級結構的人,也曾經非常接近解開 DNA 結構。

說到鮑林,就繞不開 51 號照片。很多人相信,如果不是富蘭克林那張 X 射線衍射照片被沃森和克里克看到,解開 DNA 結構的人可能就是鮑林。

科爾金說,科學就是這麼一場有趣的競賽。

一個百奈米的東西,如何改變了所有人

最後一個問題有點大:研究人體的防禦系統,研究這些敵人,會不會改變你對自己生命的看法?

科爾金的回答很直接。

"它讓我意識到人的生命有多脆弱。一個極小極小的東西,能對整個全人類的生活造成這麼大的影響。所以這值得我們珍惜,也值得記住:我們是脆弱的,我們必須作為一個社會聯結在一起。它也給了我希望,讓我相信科學家做的事情是有用的。"(德米特里·科爾金)

這場對話發生在 2020 年 4 月。回頭看,其中不少判斷都站得住:抗病毒藥物會是短期答案,無症狀傳播是關鍵變數,口罩在兩個方向上都有用,通用疫苗是長期的科學目標。

也有不少當時還懸而未決的問題,後來陸續有了答案。這正是這類對話的價值所在,它記錄的是一個領域在最不確定的時刻,專家們是怎麼思考的。

節目最後,Lex 引用了 E.O. 威爾遜的一句話:地球上病毒所攜帶的基因種類,很可能超過其餘所有生命加起來的總和。

一個連"活著"都算不上的東西,基因多樣性卻壓倒了整個生命世界。它不需要複雜,它只需要夠用。

普通人能做的幾件事

  • 戴口罩的主要意義是保護別人。至少 30% 的感染者完全沒有症狀卻仍在排毒,你沒法靠"看起來健康"來判斷誰安全。
  • 別指望 18 個月出疫苗是"慢"。歷史上從設計到量產可能要十年,這已經是極度加速,也意味著不確定性依然很大。
  • 如果關心抗病毒藥物,重點看結合位點有沒有突變,別隻看藥物名字有多新。科爾金團隊的發現是,已知藥物的靶點大多完好,這條路徑比開發全新藥物更快見效。
  • 想入門計算生物學,從公開資料開始。蛋白質資料庫(PDB)幾十年來一直免費開放,Foldit 這樣的專案讓普通人也能參與蛋白質摺疊,玩家解出的結構甚至比演算法更好。
  • 關注預印本平臺。這場疫情把"知識本身比期刊更重要"這件事擺到了檯面上,最快的科學進展往往不在正式期刊上,而在還沒經過完整同行評議的預印本里。
  • 別把病毒擬人化。它沒有意圖,沒有惡意,只是一臺被進化打磨到極致的機器。理解它的結構,比恐懼它更有用。
文稿由本站用語音識別模型(基於官方釋出音訊)機器轉寫,可能有識別錯誤,人名與數字請以音訊為準。
[00:00:00] The following is a conversation with Dmitri Korkin, he's a professor of bioinformatics and computational biology at WPI Worcester Polytechnic Institute, where he specializes in bioinformatics of complex diseases, computational genomics systems, biology and biomedical data analytics. I came across Dmitri's work when in February, his group used the viral genome of the covid-19 to reconstruct the 3D structure of its major viral proteins and their interaction with the human proteins, in effect creating a structural genomics map of the coronavirus and making this data open and available to researchers everywhere. [00:00:40] We talked about the biology of covid-19, SARS and viruses in general, and how computational methods can help us understand the structure and function in order to develop antiviral drugs and vaccines. This conversation was recorded recently in the time of the coronavirus pandemic for everyone feeling the medical, psychological and financial burden of this crisis. I'm sending love your way. Stay strong. We're in this together. Will beat this thing. This is the artificial intelligence podcast, if you enjoy it, subscribe on YouTube, review it with five stars, an app, a podcast supported on page one or simply connected me on Twitter. [00:01:19] Allex Friedman spelled F.R. Idi Amin. This show is presented by Kashyap, the number one finance app in the App Store, when you get it, is called Legs Podcast. Cash App. As you said, my friends buy Bitcoin and invest in the stock market with as little as one dollar since cash allows you to buy Bitcoin. Let me mention that cryptocurrency in the context of the history of money is fascinating. I recommend Ascent of Money as a great book on its history. [00:01:48] Debits and credits and ledgers started around 30000 years ago, the US dollar created over two hundred years ago, and Bitcoin, the first decentralized cryptocurrency released just over 10 years ago. So given that history, cryptocurrency is still very much in its early days of development, but it's still aiming to and just might redefine the nature of money. So, again, if you get cash out from the App Store or Google Play and use the Culex podcast, you get ten dollars in cash. [00:02:19] Apple also donate ten dollars. The first, an organization that is helping to advance robotics and stem education for young people around the world. And now here's my conversation with Dmitri Korkin. Do you find viruses terrifying or fascinating? When I think about viruses, I think about them. I mean, I imagine them as those villains that do their work so perfectly well, that's that is impossible not to be fascinated with them. So what do you imagine when you think about a virus? [00:03:17] Do imagine the individual sort of these 100 nanometre particle things, or do you imagine the whole pandemic like society level? [00:03:28] The when you say the efficiency of which they do their work, do you think of viruses as the millions that that occupy a human body or a living organism society level like spreading as a pandemic? Or do you think of the individual little guy as this is? I think this is a unique and unique concept that allows you to move from microscale to the macro scale, isolate the virus itself. I mean, it's it's not a living organism. It's a machine. [00:04:03] To me, it's a machine, but it is perfected to the way that it essentially has a limited number of functions. It needs to do the necessary functions and it essentially has enough information just to do those functions as well as the ability to modify itself. So, you know, it's it's a machine, it's an intelligent machine, so, yeah, maybe on that point you're in danger of reducing the power of this thing by calling it a machine. [00:04:41] Right. But you now mentioned that it's also possibly intelligent. It seems that there are these elements of brilliance that a virus has, of intelligence, of maximizing. So many things about his behavior and to ensure its survival and its and its success. So do you see it as intelligent? So, you know, I think the it's a different I understand it differently than, you know, I think about, you know, intelligence of humankind or intelligence of of the of the you know, of the artificial intelligence. [00:05:28] Mechanisms. I think the intelligence of a virus is in its simplicity, the ability to do. So much with so little material and information. But also, I think it's interesting, it keeps me thinking, you know, it keeps me wondering whether or not it's also the the an example of the basic swarm intelligence. [00:06:08] Where essentially the viruses act as the hole and they're extremely efficient in that. So what do you attribute the incredible simplicity and the efficiency to, is it the evolutionary process to maybe another way to ask that if you look at the next hundred years, are you more worried about the natural pandemics or the engineered pandemics? So how hard is it to build a virus? Yes, it's it's a very, very interesting question because obviously there is a lot of conversations about. [00:06:49] The you know, whether we are capable of engineering a, you know, an even worse a virus, I personally expect and am mostly concerned with the naturally occurring viruses simply because we keep seeing that we keep seeing new strains of influenza emerging, some of them becoming pandemic. [00:07:19] We keep seeing new strains of coronaviruses emerging. This is a natural process. And I think this is why it's so powerful. You know, if you ask me. You know, I've read papers about scientists trying to study the capacity of the modern, you know, biotechnology to alter the virus's. But I hope that that. You know it, and it won't be our main concern in the near future. What do you mean by. Hope. Well, you know, if you look back and look at the history of the of the most dangerous viruses, so that's the first thing that comes to mind is a smallpox. [00:08:26] So right now there is. Perhaps a handful of places where this, you know, the strains of this virus. Are stored, right? So this is essentially the effort of the whole society to limit the access to those viruses. [00:08:49] You mean in the lab, in a controlled environment in order to study? [00:08:53] And then smallpox is one of the viruses for which this should be stated. There's a vaccine is developed. Yes. Yes. And that's you know, it's until scientists it I mean, in my opinion, it was perhaps the most dangerous. Thing that was there is that a very different virus than than the influenza and coronaviruses? It is it is different in several aspects. [00:09:26] Biologically, it's a so-called double stranded DNA virus, but also in the way that it is much more contagious. So they are not for. So this is this is the courts are not are not is essentially an average number. As a person infected by the virus can spread to other people, so then the average number of people that he or she can, you know, spread it to. And, you know, the there is still some, you know, discussion about the estimates of the current virus, you know, the estimations vary between, you know, one point five and three. [00:10:24] In case of smallpox, it was five to seven. And we're talking about the exponential growth, right? Yes, so that's that's a very big difference. It's not the most contagious one, measles, for example, it's, I think, 15 and up, so so it's it's you know, but it's definitely, definitely more contentious that the seasonal flu than. [00:11:00] The current coronavirus or SARS, for that matter. So what makes what makes the virus more contagious? I'm sure there's a lot of variables that come into play. But is it is that that whole discussion of aerosol and like the size of droplets, if it's airborne or is there some other stuff that's more biology center? [00:11:22] I mean, there are a lot of components and there are biological components that there are also, you know, social components, the ability of the virus to, you know, the the ways in which the virus is spread is definitely, one, the ability to virus to stay on the surfaces. To survive the ability of the virus to replicate. Fast, also, once it's in the cellar, whatever you want, once it's inside the host, and interestingly enough, something that. [00:12:01] I think we didn't pay. That much attention to is the incubation period, the were you know, hosts are symptomatic, and now it turns out that another thing that we one really needs to take into account the percentage of the symptomatic population. Because those people still had this virus and still are, you know, they still are contagious. So there's the Iceland study, which I think is probably the most impressive size wise shows 50 percent asymptomatic for this virus. [00:12:41] I also recently learned the swine flu. [00:12:46] Is like the just the number of people who got infected was in the billions, it was some crazy number. It was like. [00:12:56] It was like. Like 20 percent of the people, 30 percent of the population, something crazy like that, so the lucky thing there is the fatality rate is low. But the fact that a virus can just take over an entire population so quickly, yes, it's terrifying, I think. I mean, this is you know, that's perhaps my favorite example of a butterfly effect, because it's really I mean, it's it's even tinier than a butterfly. And look at, you know, and with, you know, if you think about it. [00:13:30] So it used to be in in those bat species and perhaps because of, you know, a couple of small changes in the individual genome is first had, you know, become capable of jumping from bats to human and then it became capable of jumping from human to human rights. [00:13:56] So this is this is I mean, it's not even the size of a virus is the size of several, you know, the several atoms or so, you know, a few atoms and over this change. [00:14:11] Has such a major impact, so is that a mutation on a single virus, is that like so if we talk about those, though, the flap of a butterfly wing, like, what's the first flap? [00:14:26] Well, I think this is the the the mutations that make that made this virus. Capable of jumping from bad species to human. Of course they are. You know, the scientists are still trying to find I mean, they still even trying to find the who was the first infected try the patient zero. The first human. The first human infected. All right. I mean, the fact that there are coronaviruses, different strains of coronaviruses in various bird species, I mean, we know that. [00:15:00] So so we you know, virologist Upshaw's them. They studied them. They look at their own genomic sequences. They are trying, of course, to understand what make this virus to jump from from bats to human. [00:15:18] There was, you know, similar to that. And, you know, in influenza, there was I think a few years ago there was this, you know. [00:15:29] Interesting story where several groups of scientists studying influenza virus essentially, you know, made experiments to show that this virus can jump from one species to another. You know, by changing, I think, just a couple of residues. And, of course, it was very controversial. I think there was a moratorium on this study for a while. But then the study was released. It was published. So why was there a moratorium? [00:16:07] Because it shows through engineering it, through modifying it. You can make it jump. [00:16:13] Yes. Yes, I I personally think it is important to study this. I mean, we should be informed. We should try to understand as much as possible in order to prevent it. But so then the engineering aspect there is. Can't you then just start searching because there's so many strands of viruses out there, can't you just search for the ones in bats that are the deadliest from the virologists perspective and then just try to engineer, try to see how to? [00:16:51] But see, that's a there's a nice aspect to it. The really nice thing about engineering viruses has the same problems. Nuclear weapons is it's hard for it to not lead to mutual self-destruction. [00:17:07] So you can't control a virus that can be used as a weapon, right? Yeah. [00:17:11] That's why I you know, in the beginning, I said, you know, I'm hopeful because there are definitely, definitely regulations to be needed to be introduced. [00:17:23] And I mean, as the scientific society is, we are in charge of, you know, making the right. Actions making the right decisions, but I think we we will benefit tremendously by understanding the mechanisms by which the virus can jump, by which the virus can become more, you know, more more dangerous to humans. [00:17:58] Because all this answers with. You know, eventually to to designing better vaccines, hopefully universal vaccines, right, and that would be a triumph of the of science. [00:18:14] So what's the universe of vaccines? Is that something that. Well, how universal is universal? Well, I mean, you know, so what's the dream? I guess because you kind of mentioned the dream of this. [00:18:24] I would be extremely happy if, you know, we designed the vaccine that is able I mean, I'll give you an example. [00:18:33] I saw. So every year we do a seasonal flu shot. The reason we do it is because, you know, we are in the arms race. You know, our vaccines are in the arms race with was constantly changing virus. Right. Now, if. [00:18:53] The next pandemic influenza pandemic will a cure, most likely this vaccine will not save us, right. Although it's it's you know, it's the same virus might be different strain. [00:19:09] So if we're able to essentially design a vaccine against, you know, influenza A virus, no matter what the strain, no matter which species did it jump from, that would be I think that would be a huge, huge progress and advancement. [00:19:31] You mentioned smallpox until the 70s might have been something that you would be worried the most about. [00:19:38] What about these days? Well, we're sitting here in the middle of a. covid-19 pandemic, but these days, nevertheless, what is your biggest worry, virus wise? What are you keeping your eye out on? [00:19:55] It looks like and, you know, based on the past several years of the of the new viruses emerging, I think. We're still dealing with different types of influence. I mean, it's also the age seven and nine avian flu that was, uh, that emerged, I think a couple of years ago in China. [00:20:25] I think the the mortality rate was incredible. I mean, it was, you know, I think above 30 percent, you know, so this is this is huge. [00:20:37] I mean, luckily for us. This strain was not pandemic, I saw it was jumping from birds to human, but I don't think it it it was actually transmittable between the humans. And, you know, this is actually a very interesting question, which scientists try to understand. Right. So they balance the delicate balance between the virus being very contagious. Right. So efficient and spreading and virus to be very pathogenic. You know. Causing, you know, harms, you know, and that's due to their. [00:21:22] So it looks like that the more pathogenic the viruses. [00:21:29] The less contagious it is. Is that a property of biology or what is it what is? I don't have an answer to that. And I think this is this is still an open question. [00:21:40] But, you know, if you look at, you know, you know, with the coronavirus, for example, if you look at, you know, the the deadlier relative murse, murse was never a pandemic virus. Right. But the you know, the again, the the mortality rate from Mars is far above, you know, I think 20 or 30 percent. So. So whatever is making this all happen doesn't want us dead. Because it's balancing out nicely, I mean, how do you explain that one not dead yet? [00:22:23] They because so many viruses and they're so good at what they do. Why do they keep us alive? [00:22:31] I mean, we will also have, you know, a lot of protection, so the immune system and so I mean, we do have, you know, ways to to fight against those viruses. And I think with the now we're much better equipped. So with the discoveries of vaccines and, you know, there are vaccines against the the viruses that maybe 200 years ago would wipe us out completely. [00:23:07] But because of these vaccines, we are actually we are capable of eradicating pretty much fully, as is the case with smallpox. [00:23:16] So if we could we go to the basics, a little bit of the biology of the virus. How does a virus, in fact, the body? [00:23:25] So I think there are some key steps that the virus needs to perform, and of course, the first one, the viral particle needs to get attached to the host cell in the case of coronavirus. [00:23:42] There is a lot of evidence that it actually interacts in the same way of the as the SARS coronavirus. So it gets attached to AC2 human receptor. And so there is I mean, as we speak, there is a growing number of papers suggesting it. Moreover, most recent, I think most recent results suggest that the this virus attaches more efficiently to this human receptor than SARS to just the sort of back off. So there is a family of viruses, the coronaviruses and SARS, whatever the heck for that, whatever that stands for. [00:24:30] So SARS actually stands for the disease that you get is a syndrome of acute respiratory syndrome. [00:24:38] So SARS is the first strain. There's Meurs Mercers answer. And there is yes, people. Scientists actually know more than three strains. I mean, so there is the Mikveh strain, which is considered to be a canonical model disease model in mice. And so there is a lot of work done on on this virus because it's but it hasn't jumped to humans yet. Yes, it's fascinating. So imagine a C two. So the when you say attach proteins are involved on both sides. [00:25:24] Yes. So we have you know, so we have this infamous spike protein on the surface of the virion particle. And it does look like a spike. And I mean, that's essentially because of this protein called the coronavirus coronavirus. So that's what makes Caronna on top of the surface. So so this virus, this protein, it actually it acts so it doesn't act alone. It actually it makes a a three copies and it makes so-called Tramer. So this tramer is essentially a functional unit, a single functional unit that it starts interacting with the AC2 receptor. [00:26:12] So this is again, another protein that now sits on the surface of a human cell with host cell, I would say. And that's essentially in that way, the virus, Anker's itself to the host cell because then it needs to actually it needs to get inside. You know, it fuses its membrane with the host membrane. [00:26:41] It releases the the key components. [00:26:45] It releases its, you know, RNA and then essentially hijacks the the machinery of the cell because. None of the viruses that we know of. Have ribosome the the machinery that allows us to print out proteins, so in order to print out proteins that are necessary for functioning of this virus, they actually needs to hijack the horse ribosomes. [00:27:17] So virus is an RNA wrapped in a bunch of proteins, one of which is this functional mechanism of a protein that does the attachment. [00:27:25] And so. Yeah, so yeah. So if you look at this virus, there are several basic components. So we start with the spike protein. This is not the only surface protein, the protein that leaves on the surface of the viral particle. [00:27:41] There is also perhaps the the protein was the highest number of copies is the membrane protein. [00:27:51] So it's essentially it forms the capture of the envelope of the protein of the viral particle and essentially, you know, helps to maintain a certain curvature, helps to make certain curvature. Then there is another protein called envelope protein or protein, and that it actually occurs in in far less quantities. And still there is ongoing research. What exactly does this protein do? [00:28:31] So these are sort of the three major surface proteins that make the the viral envelope. [00:28:39] And when we go inside, then we have another structural protein called nuclear protein. And the the purpose of this protein is to protect the viral RNA that actually binds to the viral RNA, creates a capsid. And so the rest of the virus, viral information is inside of this orany and. You know, if you compare the amount of the genes or, you know, proteins that are made of these genes, it's much it's significantly higher than of influenza virus, for example, influenza virus, because I think around eight or nine proteins where this one has at least twenty nine. [00:29:30] Wow. That has to do with the length of the RNA strand. [00:29:34] I mean so I mean, so it affects the length of the hour in this turn. So, so, so because you essentially need to have sort of the minimum amount of information to encode those genes. How many proteins did you say. [00:29:48] Twenty nine. Nine proteins. Yes. [00:29:52] So, so this is this is, you know, something definitely interesting because, you know, believe it or not, we've been studying, you know, coronaviruses for over two decades. We've yet to uncover all functionalities of these proteins. Could we maybe take a small change? And can you can you say how one would try to figure out what a function of a particular protein is? So you've mentioned people are still trying to figure out what the function of the individual protein might be or what's the process. [00:30:29] So this is where the research that computational scientists do might be of help because, you know, in the past several decades was that we actually have collected a pretty decent amount of knowledge about different proteins in different viruses. [00:30:51] So what we can actually try to do, and this is sort of could be sort of our first lead to a possible function, is to see whether those, you know, say we have this genome of the coronavirus, although of the novel coronavirus, and we identify the potential proteins. [00:31:14] Then in order to infer the function, what we can do, we can actually see whether those proteins are similar to those ones that we already know. OK, in such a way, we can, you know, for example, clearly identify, you know, some critical components that are in a polymer E or different types of proteases. These are the proteins that essentially clip the protein sequences. And so this works in many cases. However, in some cases, you have truly novel proteins and this is a and then a much more difficult task. [00:31:58] Now, as a small pause, when you say similar, like what if some parts are different and some parts are similar, like, how do you disentangle that? You know, it's a big question, of course, you know what by fanatics does it does predictions, right? So those predictions turn. They have to be validated by experiments, functional or structural predictions? [00:32:25] Both. I mean, we do structural predictions with the functional predictions. We do interactions, predictions. [00:32:32] This is interesting. So you just generate a lot of predictions like reasonable predictions, based instructional function interaction, like you said. And then here you go. That's the power of bioinformatics. Is data grounded good predictions of what should happen? So in a way, I see it. [00:32:53] We're helping experimental scientists to streamline the discovery process and the experimental scientists that would have virologists. [00:33:04] So they have a virologist, one of the experimental sciences that focus on viruses. They often work with other experimental scientists, for example, the molecular imaging scientists. So they the the the viruses often can be viewed and reconstructed through electron microscope techniques. [00:33:29] So but these are specialists that are not necessarily biologists. They work with small, small particles, small, whether it's viruses or is it an organelle or where you know, or a human cell, whether it's a, you know, complex molecular machinery. So the techniques that are used are very similar in in sort of in its in their essence. And so. Yeah. So so typically we see it now. The research. On, you know, that is emerging and that that is needed often involves the collaborations between virologists, you know, biochemists, you know, people from pharma, pharmaceutical sciences, computational sciences. [00:34:33] So we have to work together. So from my perspective is a step back. [00:34:38] Sometimes I look at this stuff just how much we understand about RNA, DNA, how much we understand about protein, like your work, the amount of proteins that you're exploring. Is it surprising to you that we were able we descendants of apes were able to figure all of this out? Like how? So your computer scientists save me from computer science perspective. I know how to write a Python program. Things are clear, but biology is a giant mess. [00:35:12] It feels like to me from an outsider's perspective is how surprising is it? Amazing is it that we were able to figure this stuff out. [00:35:21] You know, if you look at the you know, how computational science and computer science was evolving. Right. I think it was just a matter of time that we would approach biology. So so we were started from, you know, applications to much more fundamental systems, physics, you know, and now we are or, you know, small chemical compounds. [00:35:49] Right. So now we are approaching the more complex biological systems. And I think it's a natural evolution of, you know, of the computer science of mathematics. [00:36:06] So sure, that's the computer science. I mean, even in higher level. So that to me is surprising. The computer science can offer help in this messy world. But I just mean, it's incredible that the biologists and the chemist can figure all this out or they just sound ridiculous to you that that of course, they would. [00:36:25] It just seems like a very complicated set of problems, like the the variety of the kinds of things that could be produced in the body to just just like you said. Twenty nine protamine, just getting a hand of a hang of it so quickly. It just seems impossible to me. [00:36:44] I agree. I mean, it's I have to say, we are, you know, in the very, very beginning of this journey. I mean, we we have yet to I mean, we are to comprehend, not even try to understand and figure out all the details, but we have yet to comprehend the complexity of the cell. We know that neuroscience is not even at the beginning of understanding the human mind. So where's biology set in terms of understanding the function? [00:37:23] Deeply understanding the function of viruses and cells. So sometimes it's easy to say when you talk about function, where you really referred to is perhaps not a deep understanding, but more of a understanding sufficient to be able to mess with it using an antiviral like mess with it chemically to prevent some of its function. Or do you understand the function? [00:37:48] Well, I think I think we are much farther in terms of understanding of the complex genetic disorders such as cancer, where you have layers of complexity and we, you know, as in my laboratory, were trying to contribute to that research. But we're also, you know, we're overwhelmed with how many different layers of complexity, different layers of mechanisms that can be hijacked by cancer simultaneously. And so. You know, I think biology in the past 20 years, again, from the perspective of the outsider, because I'm not a biologist, but I think it has advanced tremendously. [00:38:36] And one thing that where computational scientists and data scientists are now becoming very, very helpful is in the fact it's going from the fact that we are now able to generate a lot of information. About the cell, whether it's next generation sequencing or transcriptase mix, whether it's life imaging information, whether it is, you know, complex interactions between proteins or between proteins and small molecules such as drugs, we we are becoming very efficient in generating this information. [00:39:25] And now the next step is to become equally efficient in. Processing this information and extracting the the key knowledge from that. That could then be validated with experiment back. Yes. So maybe then going all the way back, we were talking, you said the first step is seeing if we can match the new proteins you found in the virus against something we've seen before to figure out its function. And then you also mentioned that. But there could be cases where it's a totally new protein. [00:40:00] Is there something bioinformatics can offer when it's a totally new protein? [00:40:05] This is where many of the methods and you probably are aware of the case of machine learning, many of these methods rely on the previous knowledge. Right. Right. So things that where we try to do from scratch are incredibly difficult, you know, something that we call an issue. And this is I mean, it's not just the function. [00:40:30] I mean, you know, we're we've yet to have a robust method to predict the structures of these proteins in absentia, you know, by not using any templates. Of other related proteins, so protein is a chain of amino acids, the residues, residues, yeah. And then have somehow magically maybe you can tell me they seem to fold in incredibly weird and complicated 3D shapes. Yes. [00:41:08] So that's where actually the idea of protein folding or just not the idea, but the problem of figuring out how the concept, the concept, how they fold into those weird shapes comes in. So that's another side of computational work. [00:41:26] So what can you describe what protein folding from the computational side is? And maybe your thoughts on the folding at home efforts that a lot of people know that you can use your machine to to do protein folding. So the protein folding is one of the those one million dollar price challenges. Right. So the reason for that is we have yet to understand precisely how the protein gets folded so efficiently to the point that in many cases where you you know, where you try to unfold it due to the high temperature, it actually folds back into its original state. [00:42:11] So we know a lot about the mechanisms. Right. But put putting those mechanisms together. And making sense, it's computationally very expensive, but in general, the proteins fold, can they fold in arbitrarily large number of ways? [00:42:34] Do they usually fold in a very small number? [00:42:36] Well, it's typically I mean, we tend to think that, you know, there is a one sort of canonical fault for a protein, although that there are many cases where the proteins upon the stabilisation, it can be folded into a different conformation. And this is especially true when you look at sort of proteins that in that include more than one structural unit. [00:43:03] So those structural units, we call them Protein Domain's essentially Protein Man is a single unit that typically is evolutionarily preserved, that typically carries out the single function and typically has a very distinct fault inside the structure, 3D structure organization. But turns out that if you look at human and average protein in a human cell would have to be two or three such subunits and how they are trying to fold into the sort of, you know, next level fault. [00:43:46] Right. So within subunit there's folding and then and then they fold into the larger 3D structure. [00:43:55] Right. And all of that. There's some understanding of the basic mechanisms, but not to put together to be able to fold it. We're still I mean, we're still struggling. I mean, we're we're getting pretty good about folding relatively small proteins, up 200 residues, which I mean but we're still far away from folding in larger proteins. [00:44:19] And some of them are notoriously difficult, for example, trans membrane proteins, proteins that that sit in the in the membranes of the cell that are incredibly important, but they are incredibly difficult to solve. [00:44:37] And so basically, there's a lot of degrees of freedom, how it folds. And so it's the combinatorial problem or just explodes. There's so many dimensions. [00:44:46] Well, it is a combinatorial problem, but it doesn't mean that we cannot approach it from the north, not from the boot for of force approach. [00:44:57] And so the machine learning approaches, you know, have been emerged that tried to tackle it. [00:45:04] So folding at home, I don't know how familiar with it, but is that use machine learning or is it more brute force not also folding at home? [00:45:13] It was originally and I remember I was a I mean, it was a long time ago. [00:45:18] I was a postdoc and we learned about this, you know, this game because it was originally designed as the game of the game. [00:45:28] And we you know, I took a look at it and it's interesting because it's it's really, you know, it's very transparent, very intuitive. So and from what I heard, I yet to introduce it to my son. But, you know, kids are actually getting very good at folding the proteins. And it was you know, it came to me as the as the not as a surprise, but actually as the sort of manifest of, you know, our capacity to to do this kind of to solve this kind of problems when. [00:46:12] A paper was published, published in one of this top journals with the co-authors being the actual players of this game. So and what happened is, was that they managed to get better structures than the sanctions themselves. So so that, you know, that was very I mean, it was the kind of profound revelation that. Problems that are so challenging for a computational science, maybe not that challenging for a human brain. [00:46:55] Well, that's a really good that's a hopeful message always when there's the proof of existence, the existence proof that it's possible. That's really interesting. But it seems what are the best ways to do protein folding now? So if you look at what deep mine does with our four fold alpha fold. Yes. So they kind of is. That's a learning approach. What's your sense? I mean, your background is machine learning, but is this a learnable problem? [00:47:30] Is it still a brute force or in the Garry Kasparov deep blue days? Are we in the alpha girl playing the game of God days of folding? [00:47:41] Well, I think we are we are advancing towards this direction. I mean, if you look so there is sort of Olympic game for protein folders called Casp. [00:47:53] And it's essentially it's you know, it's a competition where different teams are given exactly the same protein sequences and they try to predict their structures. Right. And of course, there are different sort of subtasks. But in the recent competition, Alpha fault was among the top performing teams, if not the top performing team. [00:48:22] So there is definitely a benefit from the data that have been generated, you know, in the past several decades, the structural data. And certainly, you know, we are now at the capacity to summarize this data, to generalize this data and to use those principles, you know, in order to predict protein structures. [00:48:51] As one of the really cool things here is there's maybe you can comment on it. There seems to be these open data sets of protein. [00:49:00] How did that with protein databank, the protein databank? [00:49:05] I mean, that's crazy. Is this a recent thing for just the A virus or is it? It's been for many, many years. I believe the first protein databank was designed on flash cards and so on. [00:49:22] So, yes, it's this I mean, this is a great example of the community efforts of everyone contributing, because every time you solve a protein or protein complex, this is where you submit it. And, you know, the scientists get access to it, scientists get to test it, and we buy morticians use this information to, you know, to make predictions. So there's no there's no culture of, like, hoarding discoveries here, so that's good. [00:50:06] I mean, you've you've you've released a few or a bunch of proteins or a matching whatever. We'll talk about details a little bit. [00:50:14] But it's kind of amazing that that's the it's kind of amazing how open the culture here is. It is. And I think this pandemic actually demonstrated. The ability of scientific community. Do you know how to solve this challenge collaboratively and this is I think it if anything, it actually moved us to a brand new level of collaborations of the efficiency in which people establish new collaborations in which people are offered their help to each other. [00:51:00] Scientists offer their help to each other and publish results to is very interesting. We're now trying to figure out as a few journals that are trying to sort of do the very accelerated review cycle, but so many preprint. So just posting a paper going out, I think it's fundamentally changing the the way we think about papers. Yes. I mean, the way we think about knowledge now, let's say yes, because. Yes, I completely agree. [00:51:29] I think now. It's. The knowledge is becoming sort of the core value, not the paper or the journal where this knowledge is published. [00:51:44] And I think this is, again, this we are living in the in the Times where it becomes really crystallized that the idea that the most important value is in the knowledge. [00:52:01] So maybe you can comment like what do you think the future of that knowledge sharing looks like? So you have this paper that I hope you get a chance to talk about a little bit, but it has like a really nice abstract in the introduction or like it has all the usual I mean, probably took a long time to put together. [00:52:18] So but is that going to remain like you could have communicated a lot of fundamental ideas here in a much shorter amount that's less traditionally acceptable by the journal context. [00:52:33] So, so. Well, you know, so the first version that we. Posted not even on the Bierko, because Bierko back then, it was essentially, you know, overwhelmed with the number of submissions. [00:52:51] So so our submission, I think it took five or six days just for it to be screened and put online. [00:53:01] So we essentially we put the first preprint on our website and, you know, it started getting access right away. So and, you know, so so this original preprint was in a much rougher shape than this paper. And but we tried I mean, we we honestly tried to be as compact as possible with, you know, introducing the the information that is necessary that the two explain our, you know, our results. [00:53:44] So maybe you can dive right in if it's OK. Sure. So there's a paper called Structural Genomics of SARS. How do you pronounce sars-cov-2 covid to. Yeah, whether it covid is such a terrible name, but it's stuck. And yes, sars-cov-2 indicates evolutionary conserved functional regions of viral proteins. So this is looking at all kinds of proteins that are part of. [00:54:13] The novel coronavirus and how they match up against the previous other kinds of coronaviruses, I mean, there's a lot of beautiful figures. I was wondering if you could I mean, there's so many questions I could ask her, but maybe at the how do you get started doing this paper? [00:54:29] So how do you start to figure out the 3D structure of a novel virus? Yes. [00:54:34] So there is actually a little story behind it. And so the story actually dated back in September of 2019. And you probably remember that back then we had another dangerous virus. Triple E virus is Eastern Incivilities Virus. [00:54:56] And can you maybe linger? And I have to admit, I was sadly completely unaware. [00:55:03] So so that was actually a virus outbreak that happened in New England. [00:55:09] Only the the danger and this virus was that it actually it targeted your brain. So so there were deaths from this virus. [00:55:22] It was it was, you know, transfer the main vector was mosquitoes. And obviously full time is the time where you have a lot of them in New England. And, you know, on one hand, people realize this is this is this is actually a very dangerous thing. [00:55:44] So it had an impact on the local economy. [00:55:50] The schools were closed past six o'clock. No activities outside for the kids because the kids were suffering quite tremendously from, you know, when infected from this virus. [00:56:05] How do I not know about this was is impacted? It was in the news. [00:56:10] I mean, it was not impacted to the high degree in Boston necessarily, but in the metro west area. And actually, it spread around, I think, all the way to New Hampshire, Connecticut. And you mentioned affecting the brain. [00:56:28] That's one other comment we should make. So you mentioned a EC2 for the coronavirus. So these viruses kind of attach to something in the body. [00:56:41] So it essentially attaches to the to these proteins in those cells, in the body where those proteins are expressed, where they actually have them being in abundance. [00:56:53] So sometimes that could be in the lungs. That could be in the brain, that could be. So I think what they right now, from what I read, they have the epithelial cells. Inside, so the cells essentially inside the you know, the cells that are covering the surface and also inside the nasal surfaces, the throat, the lung cells and I believe liver, a couple of other organs where they are actually expressed in abundance, that's further actually sent into receptors. [00:57:34] OK, so back to back to the story. So, yes, in the fall. [00:57:38] So now the these you know, the impact of this virus is significant. [00:57:47] However, it's a pretty local problem to the point that, you know, this is something that we would call a neglected disease because it's not big enough. To make, you know, the drug design companies to design a new antiviral or new Weixin, it's not big enough to generate a lot of grants from the national funding agencies. [00:58:22] So. [00:58:23] So does it mean we cannot do anything about it? [00:58:26] And so what they did is I thought about informatics class and is in Worcester Polytechnic Institute and we are very much a problem. [00:58:40] Learning institution, so I thought that that would be a perfect, you know, perfect project for the ongoing case study. [00:58:51] So so I asked, you know, so so I was essentially designed a study where we try to use by informatics to to understand as much as possible about this virus. And a very substantial portion of the study was to understand the structures of the proteins, to understand how they interact with each other and with the with the host proteins, try to understand the evolution of this virus. So obviously, a very important question, how where it will evolve further, how you know, how it happened here. [00:59:37] You know, so so we did all this, you know, products. [00:59:42] And now I'm trying to put them into a paper where all this undergraduate students will be co-authors, but. [00:59:51] Essentially, the projects were finished right about mid-December and a couple of weeks later, I heard about this mysterious new virus that was discovered in was reported in one province. [01:00:08] And immediately I thought that, well, we just did that. Can't we do the same thing with this virus and so we start waiting for the genome to be released because that's essentially the first piece of information that is critical. Once you have the genome sequence, you can start doing a lot using by informatics. [01:00:31] When you say genome sequence, that's referring to the sequence of letters that make up the RNA so that, well, the sequence that make up the entire information encoded in the protein. Right. So. [01:00:46] So that includes all twenty nine genes. What are genes, what's the encoding of information, social genes is essentially is the basic functional unit. [01:01:03] That we can consider also each gene in the virus would correspond to a protein that so gene by itself doesn't do it function, it needs to be converted or translated into the protein. That will become the actual functional unit, you know, like you said, the printer, so so we need the printer for that. We need the printer. OK, so the first step is to figure out that the genome, the sequence of things that could be then used for printing the protein. [01:01:39] So, OK, so then the next step. So so once we have this and so we use the existing information about sars-cov-2, the source genomics has been done. In abundance, so we have different strains of of SARS and actually other related coronaviruses murse the bat coronavirus, and we started by identifying the potential genes, because right now it's just the sequence of the sequence that is roughly it's less than 30000 thousand nucleotides long. [01:02:22] And just the raw sequence, it's a Rossignol, that information really. And we now need to define the boundaries of the genes that would then be used to identify the proteins and protein structures. [01:02:39] How hard is that problem? It's not I mean, it's pretty straightforward. [01:02:45] So, you know, so because we use the existing information about such proteins and the genes. [01:02:53] So once again, you kind of we are relying on the. [01:02:57] Yes. So. [01:02:58] And then once we get there. This is where sort of the first more traditional informatic steps step begins, we're trying to use this protein sequences and get the 3D information about those proteins. So this is where we are relying heavily on the structure information, specifically from the protein databank that we are talking about, and here you're looking for similar proteins. [01:03:36] Yes. So so the the concept that we are operating when we do this kind of modeling, it's called homology or template based modeling. [01:03:45] So essentially using the concept that if you have two sequences that are similar in terms of the letters, the structures of the sequences are expected to be similar as well. And this is at the micro at the very local scale and at the scale of the whole problem, the whole protein I saw actually saw the. [01:04:12] Of course, the devil is in the details, and this is why we need actually. Pretty sophisticated modeling tools to do so. Once we get the structures of the individual proteins, we try to see whether or not these proteins act alone or they have to be forming protein complexes in order to perform this function. And again, so this is sort of the next level of the modeling because now you need to understand how proteins interact. And it could be the case that the protein interacts with itself and makes sort of a a multi Merick complex, the same protein just repeated multiple times. [01:05:11] And we have quite a quite a few such proteins in sars-cov-2 to specifically spike protein needs three copies to function and protein needs five copies to function. And there are some other multimeter complexes that we mean by interacting with itself. [01:05:38] And you see multiple copies. So how do you how do you make a good guess whether something is going to interact? Well, again, so there are two approaches. [01:05:46] So one is look at the previously solved complexes. Now we're looking not at the individual structures, but the structures of the whole complex complex is about multiple proteins. [01:06:00] Yes. So it's a bunch of proteins essentially glued together. And when you say glue, that's the interaction. That's the interaction source. So the different forces, different sort of physical forces behind this. [01:06:14] And so sorry to keep asking them questions, but is it is it is that the interaction fundamentally structural or is it functional like in the way you're thinking about it? [01:06:27] That's actually a very good way to ask this question, because it turns out that the interaction is structural, but in the way it forms the structure, it actually also carries out the function. [01:06:45] So interaction is often needed to carry out very specific function of a protein, but in terms of another side, figuring out you're really starting at the structure before you figure out the function. [01:07:01] So there's a beautiful figure, too, in the paper of all the different proteins that make up the able to figure out the makeup. [01:07:13] The the new the novel coronavirus, what what are we looking at? So these are like. [01:07:22] That's the through the step to the you mentioned, when you try to guess at the possible proteins, that's what you're going to get is blue blue cyan blobs. Yes. So so those are the individual proteins for which we have. [01:07:40] At least some information from the previous studies. So there is advantage and disadvantage of using previous stages. The biggest well, the disadvantage is that, you know, we may not necessarily have the coverage of all 29 proteins. However, the biggest advantage is that the accuracy in which we can model these proteins is very high, much higher compared to when you show methods that do not use any template information. [01:08:14] So but nevertheless, this figure also has a beautiful and of a lot of these pictures, so much UV as it has the pink parts are the parts that are different. [01:08:27] So you're highlighting the difference you find is on the 2D sequence and then you try to infer what that will look like on the 3D. [01:08:35] Yeah, so so the difference actually is on one sequence, one one designed to do so. And so this is one of the first questions that we are trying to answer is that, well, if you take this new virus and you take the closest relatives, which are SARS and a couple of bat coronavirus strains. They are already the closest relatives that we are aware of. Now, what are the difference between this virus and this close relatives? And what if you look typically when you take a sequence, those differences could be quite far away from each other. [01:09:25] So what make what 3D structure makes those difference to do? They very often they tend to cluster together. [01:09:36] And over sudden, the differences that may look completely unrelated actually relate to each other. And sometimes they are there because they correspond. They attack the functional side. Right. So they are there because this is the functional side that is highly mutated. So that's a computational approach to figuring something out. And when when it comes together like that, that's kind of a nice, clean indication that there is something this could be actually indicative of what's what's happening. [01:10:16] Yes. I mean, so so we need this information. And, you know, 3D, the 3D structure gives us just a very. Intuitive way to look at this information and then start to ask, you'll start asking questions such as. So this place of this protein that is highly mutated, does it? Does it? Is it the functional part of the protein, so does this part of the protein interact with some other proteins or maybe with some other Leganes small, small molecules? [01:11:00] Right. So we will try now to functionally inform. This 3D structure. [01:11:08] So we have a bunch of these mutated parts, if, like I don't like how many are there in the new novel coronavirus and compared to SARS that we're talking about, hundreds of thousands like these these pink regional nodded much less than that. [01:11:28] And it's very interesting that if you look at that and also the first thing that you start seeing, right, you know, you look at patterns. Right. [01:11:36] And the first pattern that becomes obvious is that. Some of the proteins in the new coronavirus are pretty much intact. Right. So they're pretty much exactly the same as SARS as the bat coronavirus, whereas some others are heavily mutated. Mm hmm. Right. [01:12:00] So so it looks like that the you know, the evolution. Is not is not occurring uniformly across the entire, you know, viral genome, but actually target very specific proteins. [01:12:19] What do you do with that, like from the Sherlock Holmes perspective? [01:12:23] Well, you know, so one of the of the most interesting findings we had was the fact that the viral so the binding sites on the viral surfaces that get targeted by the known small molecules, they were pretty much. [01:12:50] Not affected at all, and so that means that the same. Small drugs or small small drug like compounds. Can be efficient for the new coronavirus. So this all actually maps to the drug companies, too, like so so you're actually mapping out what old stuff is going to work on this thing and then possibilities for new stuff to work by mapping out the things have mutated. Yes. [01:13:25] So so we essentially know which parts and behave differently and which parts. Are likely to behave similar. And again, you know, of course, all our predictions need to be validated by experiments, but hopefully that sort of helps us to delineate the regions of this virus that, you know, can be promising in terms of the drug discovery. [01:13:56] You kind of you kind of mentioned this already, but maybe you can elaborate. So how different from the structural and functional perspective does the new coronavirus appear to be relative to SARS? [01:14:09] We now are trying to understand the overall structural characteristics of this virus because, I mean, that's that's our next step, trying to model the viral particle of a single viral particle of this virus. So that means that you have the individual proteins that you said you have to figure out what their interaction is. Is that where this graph kind of interacts on so? [01:14:37] So it's also the interacting with the it's essentially a. So our prediction on the potential interactions, some of them that we already deciphered from the structural knowledge, but some of them that essentially are deciphered from the knowledge of the existing interactions that people. Previously obtained Fossas for Murse or other related viruses. [01:15:07] So is there kind of interact tomes? [01:15:10] I'm pronouncing that correctly, by the way, are those already? Converge towards Fossas for so do I think there are there is there are a couple of papers that now investigate the sort of the large scale set of sets of interactions between the new SARS and its host. And so I think that's that's an ongoing study, I think. And the success of that, the result would be an attraction. Yes. And so when you say not trying to figure out the entire the circle, the entire thing. [01:15:55] All right. So if you look at the structure of what this viral particle looks like. Right. So, as I said, it's you know, the surface of it is an envelope, which is essentially a so-called lipid bilayer with proteins integrated into the surface. So how so? So an average particle is around 18 nanometers, right. So. These particle can have about 50 to 100 spike proteins. So at least we suspected, based on the micrographs images, it's very comparable to an HIV virus in mice and SARS virus micrographs or actual pictures of the actual virus. [01:16:53] OK, so these are models. This is that the actual images, right? What do they. For the tangents. But what are these things? [01:17:01] So when you look on the Internet, the models and the pictures are in the models you have here, just gorgeous and beautiful when you actually take pictures of them with the micrograph. [01:17:12] Like what? What do we look? [01:17:13] Well, they typically are not perfect. It's also the most of the images that you see now is the is the sphere with those spikes. [01:17:26] You actually see you actually. Yes. You do see the spikes. [01:17:30] And now, you know, the our collaborators for Texas A&M University, Benjamin Newman, he actually in the recent paper about he proposed and do some actually evidence behind it that the particle is not a sphere, but is actually is an elongated. Ellipsoid like particle's so. So that's what we are trying to incorporate into our model. And the I mean, you know, if you look at the actual micrographs, you see that those particles are, you know. [01:18:18] Are not symmetric, so there's some of them. And, of course, you know, it could be due to the treatment of the or the material, it could be due to the some noise in the imaging. So there's a lot of uncertainty. So, yes, OK. So structurally, figuring out the entire part, by the way, sorry for the changes, but why the term particle? [01:18:43] Or is it just it's a single, you know, so, you know, we call it the virion, so very unpolitical. It's essentially a single virus, single virus, but just feels like because particle to me from the physics perspective, feels like the the most basic unit. There seems to be so much going on inside the virus, it doesn't feel like a particle to me. Yes, well, yeah, it's probably I think it's the virion is a good way to call it so. [01:19:16] OK, so trying to figure out trying to figure out the entirety of the system. Yes. So, you know, so, you know, so this is sort of virion has 50, 200 spikes or spikes. [01:19:33] It has roughly 200 to 400 membrane protein demerse and those are arranged in a very nice lattice. So you can actually see sort of the it's like a it's a carpet of on the surface again. [01:19:53] Exactly on the surface. And occasionally you also see this envelope protein. Inside and out, the one we don't know what it does exactly, exactly, the one that that forms the pantomimed, it's very nice pentameter ring. And so, you know, so this is what we're trying to you know, we're trying to put now all our knowledge together and see whether we can actually generate this overall virion model. With an idea to understand, you know, well, first of all, to understand how how it looks like, how far it is from those images that were generated, but I mean, the implications are there is a potential for the, you know, nanoparticle design that will mimic this virion particle. [01:20:53] Is the process of nanoparticle design, meaning artificially designing something that looks similar? Yes. [01:20:59] And also the one that can potentially compete with the actual virion particles and therefore reduce the effect of the infection. So is this the idea of like what is a vaccine, a vaccine vaccine so that. [01:21:19] Yeah, so there are two ways of essentially treating and in the case of vaccine is preventing the infection. [01:21:28] So vaccine is, you know, a way to train our immune system so our immune system becomes aware of this new danger and therefore is capable of generating the antibodies, then will essentially bind to the spike proteins because that's the main target for the for for the vaccine's design and. [01:22:02] Block, it's functioning if you have the spike with the antibody on top and can no longer interact with AC2 receptor, so the the process of designing a vaccine then is you have to understand enough about the structure of the virus itself to be able to create an artificial and artificial particle. [01:22:27] Well, I mean, there's a nanoparticle. This is a very exciting and new research. So there are already established ways to, you know, to make vaccines. And there are several different ones. It's also there is one where essentially the virus gets through the cell culture multiple times. So it becomes essentially, you know, adjusted to the to the specific embryonic cell and as a result, become becomes less, you know, compatible with the host human cells. [01:23:10] So therefore, it's sort of the the the idea of the life mixin where the particles are as they are, but they are not so efficient. And also they cannot replicate, you know, as rapidly as, you know, before the vaccine. And they can be introduced to the immune system. The immune system will germ and the person who gets this vaccine won't get, you know, sick or, you know, will have mild, you know, mild symptoms. [01:23:47] So then there is sort of different types of the way to introduce the non-functional, non-functional parts of this virus or the virus where some of the information is stripped down. For example, the virus with no genetic material. So so we was looking at an age, you know. Exactly. So it cannot replicate it cannot essentially perform most of its functions. [01:24:16] They're saying, what is the biggest hurdle to design the one of these to arrive at one of these? [01:24:23] Is it the work that you're doing in the fundamental understanding of this new virus, or is it in the from our perspective, the complicated world of experimental validation and sort of showing that it's like going through the whole process of showing this is actually going to work with FDA approval, all that kind of stuff? I think it's both. [01:24:43] I mean, you know, our understanding of the molecular mechanisms will allow us to, you know, to design to have more efficient designs of the vaccines. [01:24:56] However, the ones who designed the vaccine, it needs to be tested, but when you look at the 18 months and the different projections, which seems like an exceptionally from historically speaking, maybe you can correct me, but it's even 18 months seems like a very accelerated timeline. It is. It is. [01:25:14] I mean, I remember reading about the you know, in the book about some previous vaccines that it could take up to 10 years to design and properly test a vaccine before it's mass production. So, yeah, we you know, everything is accelerated these days. [01:25:36] I mean, for better. For worse. But but, you know, we definitely need that. [01:25:41] Well, especially with the coronavirus. I mean, the scientific community is really stepping up and working together. The collaborative aspect is really interesting. You mentioned the vaccine is one and then there's antivirals, antiviral drugs. So antiviral drugs are where, you know, vaccines are typically needed to prevent the infection. But once you have an infection, what one you know? So what we try to do, we try to stop it. So we try to stop the virus from functioning. [01:26:09] And so the antiviral drugs are designed to block some critical functioning of the all of the proteins from the virus, from the virus. So there are a number of interesting candidates. [01:26:28] And I think, you know, if you ask me. I you know, I think Remedy Severe is perhaps the most promising it's it has been shown to be. [01:26:48] You know, an efficient and effective antiviral for SARS. Originally, it was the antiviral drug developed for a completely different virus, I think, for Ebola and Marburg and high levels. [01:27:07] You know how it works. So it tries to mimic one of the nucleotides in RNA and essentially that that stops the replication from. [01:27:22] So Messers, I guess that's what the antiviral drugs mess up some aspect of this. Yes. [01:27:28] Process also, you know, so essentially we try to stop certain functions of the virus. There are some other ones, you know, that are designed to inhibit the protease. [01:27:44] The thing that clip's protein sequences. There is one that was originally designed for malaria, which is a bacterial, you know, bacterial disease. [01:27:58] So this is, of course, but that's exactly where your work stops in is. You're figuring out the functional than the structure is different. So, like providing candidates for drugs can plug in? [01:28:12] Well, yes, because, you know, one thing that we don't know is whether or not. [01:28:19] So let's say we have a perfect drug candidate that is efficient against Sartin, against Murse. Now, is it going to be efficient against new sars-cov-2? We don't know that. And there are multiple aspects that can affect this efficiency. So, for instance, if the the binding sites or the part of the protein where this ligand gets attached, if this site is mutated, then the ligand may not be attachable to this part any longer. [01:28:58] And you know, our work and the work of other informatics groups, you know, essentially are trying to understand whether or not that will be the case or and it looks like for for the ligands that we looked at, the legal binding sites are pretty much intact. [01:29:23] Which is very promising, if we can just, like, zoom out for a second. What are you optimistic? So this two well, there's three possible answers to the coronavirus pandemic. So one is there's or drugs or vaccines get figured out very quickly. Probably drugs first. The other is the the the pandemic runs its course for this wave at least. And then the third is, you know, things go much worse in some in some dark, bad, very bad direction. [01:30:04] Do you see let's focus on the first two. Do you see the anti-drug side of the work you're doing being relevant? For us right now. In stopping the pandemic, or do you hope that the pandemic will run its course, so the social distancing, things like wearing masks, all those discussions that we're having will be the the method with which we fight coronavirus in the short term, or do you think that it will have to be antiviral drugs? I think, um, I think antivirals would be, uh. [01:30:50] I would view that as the at least the short term solution, I see more and more cases in the news of those new drug candidates being administered in hospitals. And I mean. This is right now the best what we have to do, we need it to re-open the economy. I mean, we would definitely need it. [01:31:19] I, I cannot sort of speculate on how that will affect reopening of the economy, because we are you know, we are kind of deep in into the pandemic. [01:31:34] And it's not just the states. It's also, you know, worldwide, you know, of course. [01:31:43] You know, there is also the possibility of the second wave, as we know and as you mentioned, and this is why, you know, we need to be super careful. [01:31:59] We need to follow all the precautions that the doctors tell us to do. [01:32:08] Are you worried about the mutation of the virus? So it's, of course, a real possibility. Now, how? To what extent this virus can mutate, it's an open question. I mean, we know that it is able to mutate to jump from one species to another and to to become transmissible between humans. Right. [01:32:37] So will it. [01:32:39] You know, so let's imagine that we have the new antiviral. Will this virus become eventually resistant to the antiviral? [01:32:50] We don't know. I mean, this is what needs to be studied. This is such a beautiful and terrifying process that a virus, some viruses may be able to mutate to respond to the mutate around the thing we've put before it. Can you explain that process? Like, how does that happen? And it just is that just the way of evolution? I would say so, yes, I mean, it's it's the evolutionary mechanisms, there is nothing imprinted into this virus that makes it, you know, it just the way it it evolves and actually it's the way it evolves with its host. [01:33:36] It's just amazing, especially the evolution mechanisms, especially amazing, given how simple the virus is, it's incredible that it's, uh, I mean, it's beautiful. It's beautiful because it's the one of the cleanest examples of evolution working. Well, I think I mean, the one of the sort of the reasons for its simplicity is because it does not require all the necessary functions. To be distort so it actually can hijack. The majority of the necessary functions from the hospital, I saw, so the ability to do so, in my view, reduces the complexity of this machine drastically. [01:34:29] Although if you look at the most recent discoveries I saw, the scientists discovered viruses that are as large as bacteria. [01:34:39] So this many viruses and mammo viruses, it actually those discoveries made scientists to reconsider the origins of the virus, you know, and what are the mechanisms and how, you know, what are the mechanisms, the evolutionary mechanisms that leads to the appearance of the viruses. [01:35:04] By the way, I mean, you did mention that viruses are. I think you mentioned that they're not living yes, they're not living organisms. Let me ask that question again. Why do you think they're not living organisms? [01:35:18] Well, because they they are dependent on the majority of the functions of the virus. [01:35:27] Are dependent on the on the cost. So let me do the devil's advocate then would be the philosophical devil's advocate here and say, well, humans, which we would say are living, need our host planet to survive. So you can basically take every living organism that we think of as definitively living. It's always going to have some aspects of its host that it needs. Of its environment. So is that really the key aspect of why a virus is that dependence, because it seems to be very good at doing so many things that we consider to be intelligent. [01:36:15] It's just that dependence part. [01:36:18] Well, I mean it. Yeah, it's it's. Difficult to. Answer in this way, I mean, I like the way I think about the virus is, you know, in order for it to function. It needs to have the critical component, the critical tools that it doesn't have. So, I mean, that's that's, you know, in my way, you know, the. It's not autonomous, I sense, and that's how I separate the the idea of the living organism on a very high level. [01:37:06] Yes. [01:37:06] Between the living organism and and you have some we have I mean, this is just terms and perhaps they don't mean much, but we have some kind of sense of what autonomous means and that humans are autonomous. You've also done excellent work in the epidemiological modeling the simulation of these things, so the zooming out outside of the body doing their agent based simulation, so that's where you actually simulate individual human beings and then the spread of viruses from one to the other. [01:37:46] How does at a high level Asian based simulation work? All right. So it's also one of this irony of timing, because, I mean, the way we we've worked on this project for the past five years and the New Year's Eve, I got an email from my student that, you know, the last experiments were completed. And, you know, the three weeks after that, we would get this diamond princess story and emailing each other with the same, you know, the same thing. [01:38:27] So the difference is a cruise ship. [01:38:29] Yes. And what was the project that you're working on, the project? [01:38:33] I mean, it's, you know, the code name. It started with a bunch of undergraduates. The code name was based on the cruise ship. And so they wanted to essentially model the the zombie apocalypse apocalypses on the cruise ship. [01:38:52] And and, you know, after having some fun with them, thought about the fact that, you know, if you look at the cruise ships, I mean, the infectious outbreak is has been one of the biggest threats to the cruise ship economy. So perhaps the most, you know, frequently occurring virus is the Norwalk virus. [01:39:19] And this is essentially one of this stomach flus that you have. [01:39:25] And, you know, it it can be quite devastating, you know, so there are occasionally there are cruise ships get you know, they get canceled, they get returned to the back to the to the origin. And so we wanted to study. And this is very different from the traditional epidemiological studies where the scale is much larger. So we wanted to study this in a confined environment, which is a cruise ship. It could be a school. [01:39:58] It could be other you know, other places such as, you know, it is a large, large company where people are in interaction. [01:40:11] And the benefit of this model is we can actually track that in real time so we can actually see the whole course of the evolution of the whole course of the interaction between the infected infected horse and, you know, the horse and the pathogen, et cetera. [01:40:38] So so agent based system or multi agent system to be precisely is a good way to approach this problem, because we can introduce the behavior of the of the passengers of the cruise and what we did for the first time. [01:41:07] That's where, you know, we introduce some novelty is we introduce a pathogen agent explicitly. So that allowed us to essentially model the behavior on the cost side as well on the pathogen side. And over sudden, we can we can have a flexible model that allows us to integrate all the key parameters about the infections. So, for example, the virus. So the ways of of transmitting the virus between the the horse. How long does a virus survive on the surface? [01:42:01] Might. What is you know, how much of the viral particles does a horse shed when he or she is a symptomatic versus symptomatic? [01:42:20] You can encode all of that into this pattern just for people who don't know. So agent based simulation, usually the agent represents a single human being. [01:42:29] And then there's some graphs that contact graphs that represent the interaction between us human beings. So, yes, so we see essentially, you know, so so agents are, you know, individual programs that are running parallel. And we're saying we can provide instruction instructions for these agents, how to interact with each other, how to exchange information in this case, exchange the the infection. [01:43:02] But in this case, in your case, you've added a pathogen as an agent. I mean, it's kind of fascinating. [01:43:08] It's a and it's kind of a brilliant, like a brilliant way to condense the parameters to to aggregate to bring the parameters together that represent the pathogen, the virus. [01:43:21] Yes, that's fascinating, actually. [01:43:24] So, yeah, it was a we realized that, you know, by bringing in the virus, we can actually start modeling. [01:43:32] I mean, we're not no longer bounded by very specific sort of aspects of the specific virus. So we end up we started with, you know, Norwalk virus and of course, zombies, but we continue to modeling Ebola virus outbreak, flu, SARS. And because I felt that we need to add a little bit more sort of excitement for our undergraduate students. [01:44:08] So we actually modeled the virus from the Contagion movie. Yes. So MTV won. And, you know, unfortunately, that virus and we try to extract as much information. [01:44:24] Luckily, the this movie was the scientific consultant was Ian Lipkin and virologist from Columbia University who is actually who provided I think he designed this virus for this movie based on me virus. [01:44:44] And I think with some ideas behind SARS of flu, like airborne viruses. [01:44:51] And, you know, the the movie surprisingly contained enough details for us to extract and to model it. I was hoping you would like publish a paper of how this virus works. Yeah, we are planning to publish. I would love it if just would be nice if the, you know, of the the the origin of the virus. But you're now actually being a scientist and studying the virus from that perspective. [01:45:19] But the origin of the virus, you know you know, the first time I actually saw this movie is assignment number one in my brain for this class that they give, because it it also it tells you that, you know, when families can be of use, because if I don't know you. Have you watched it a long time ago. And so so there is, you know, approximately a week from the, you know, virus detection. We see a screenshot of scientists looking at the structure of the surface protein. [01:45:56] And this is where I tell my students that, you know, if you ask experimental biologists, they will tell you that it's impossible because it takes months, maybe years to get the crystal structure of this. [01:46:11] You know, the structure that is represented. If you ask by a magician, they tell you, sure, why not just get it model. Yeah. [01:46:21] And and yes, but but it was very interesting to to see that there is actually, you know, and if you do it's do screen shots, you actually see the feel of genetic tree, the evolutionary tree that relate this virus with other viruses. So it was a lot of scientific thought put into the movie. And one thing that I was actually it was interesting to learn is that the origin of this virus was that I. Two. [01:46:56] Animals that led to the you know, the the you know, the zoonotic origin of this virus were fruit bat and a pig. So, you know, so so. [01:47:10] So this is this is this is this doesn't feel like this. This definitely feels like we're living in a simulation. [01:47:18] OK, maybe big picture. Ajimobi simulation, now largescale sort of not focused on a cruise ship, a large scale I use now to drive some policy. So politicians used to tell stories and narratives and try to figure out how how to move forward. And there's so much so much uncertainty. But in your sense, our simulation useful for actually predicting the future, or are they useful mostly for comparing relative comparison of different intervention methods? [01:47:55] Well, I think both because, you know, in the case of new coronavirus. [01:48:03] We we essentially learning that the current intervention methods may not be efficient enough. One thing that one important aspect that I find to be. So critical. And yet. Something that was overlooked, you know, during the past pandemics is the effect of the asymptomatic period. This virus is different because it has such a long asymptomatic period and over sudden that creates a completely new game when trying to contain this virus enters the dynamics of the infection. [01:48:54] Exactly. I do also I don't know how closely you're tracking this, but do you also think that there's a different, like, rate of infection from when you're asymptomatic like that? [01:49:10] That aspect or does a virus not care? So there were a couple of works. [01:49:17] So one important parameter that tells us how contagious the the person was asymptomatic to us versus asymptomatic is looking at the number of viral particles. [01:49:34] This person sheds. You know, as a function of time, so so far what they saw is. The study that tells us that the you know, the person during their symptomatic period is already contagious and it spreads the person spreads enough viruses to infect in another host. [01:50:05] And I think there's too many excellent papers coming out. But I think I just saw some maybe in Nature paper that said the first week is when you're. Asymptomatic or asymptomatic, you're the most contagious of the highest level of the like the plot sort of in the 14 day period, they collected a bunch of subjects. [01:50:26] And I think the first week is when it's the most. [01:50:29] Yeah, I think I mean, I'm waiting and waiting to see sort of more more populated stages or just those higher numbers. [01:50:40] Um, my one of my favorite stages was, again, very recent one where scientists determined that, um. Here's. I'm not contagious, so so there is, you know, so there is no viral shedding down through the years, so we found one more thing that's not contagious. [01:51:08] And I mean, there's a lot of I've personally been because I'm going to survey paper somehow this looking at masks. And there's been so much interesting debate on the efficacy of masks. And there's a lot of work and there's a lot of interesting work on whether this virus is airborne. I mean, it's a totally open question. It's leaning one way right now, but it's a totally open question whether he can travel and aerosols long distances. I mean, do you have ever do you think about the stuff to track this stuff? [01:51:43] Are you focused on the. [01:51:44] Yeah, I mean, it I mean, this is this is a very important aspect for our epidemiology study. [01:51:54] I think the I mean and it's sort of a very simple sort of idea. But I agree with people who say that the mask. The masks work in both in both ways, so it not only protects you from the, you know, incoming viral particles, but also, you know, it it, you know, makes the potentially contagious person not to spread the virus particles when they're asymptomatic may not even know that they're exactly. [01:52:32] In fact, it seems to be there's evidence that they don't surgical and certainly homemade masks, which is what's needed now, actually, because there's a huge shortage of they don't work as to protect you that well, they work much better to protect others. So that's the motivation for us to all wear one. Exactly. [01:52:55] Because, I mean, you know, very you don't know where you are and you know, about 30 percent as far as I remember, at least 30 percent of the asymptomatic cases are completely asymptomatic there. Right. So you don't really cough. You don't I mean, you don't have any symptoms yet. [01:53:14] You shed viruses. Do you think it's possible they will all wear masks? So I wore a mask at the grocery store and you just you get looks. I mean, this was like a week ago. Maybe it's really changed because I think CDC or somebody I think the CDC has said that we should be wearing masks like L.A. They're starting to happen. But it just seems like something that this country will really struggle doing or. No, I hope not. [01:53:43] I mean, you know, it was interesting. I was looking through the through the old pictures during the Spanish flu, and you could see that the you know. Pretty much everyone was wearing masks, with some exceptions, and they were like, you know, sort of iconic photograph of the I think it was San Francisco, this tram, who was refusing to let in a, you know, someone without the mask. [01:54:16] So I think well, you know, it's also, you know, it's related to the fact or, you know, how much we are scared. Right. [01:54:28] So how much do we treat this problem seriously? And. You know. My take on it is we should. Because it is very serious. Yeah, I from a psychology perspective, just worry about the entirety of the entire big mess of a psychology experiment, that this is whether the mask will help it or hurt it. You know, masks have a way of distancing us from others by removing the emotional expression and all that kind of stuff. But at the same time, mask also signal that I care about your well-being. [01:55:15] So that's a really interesting trade off. That's just the idea. It's it's interesting, right, about distancing. And we distanced enough. [01:55:25] Right, exactly. I mean, and when we try to come closer together, when they do reopen the economy, that's going to be a long road of rebuilding trust and not not all being huge germophobia. [01:55:41] Yes. Let me ask. [01:55:42] Sort of. You have a bit of a Russian accent, Russian or no Russian accent, so were you born in Russia? Yes. And the you you're too kind. [01:55:55] I have a pretty thick Russian accent. [01:55:59] What are your favorite memories of Russia? So I so I moved first to Canada and then to the United States back in '99. So by that time I was 22. [01:56:14] So, you know, whatever Russian accent I got back then, you know, it's stuck with me for the rest of my life. [01:56:24] Uh. [01:56:26] You know, it's yeah, so I you know, by the time the Soviet Union collapsed, I was, you know, I was a kid, but sort of, you know, old enough to to realize that there are changes. [01:56:44] And did you want to be a scientist back then? Oh, yes. Oh, yeah. I mean, my first, uh, the first sort of 10 years of my sort of, uh, you know, juvenile life. I wanted to be a pilot of a passenger jet plane. Wow. [01:57:09] So, yes, it was like, you know, and I was getting ready, you know, to to go to a college to get the degree. [01:57:19] But I've been always fascinated by science and, you know, so not just by math. Of course, my son was one of my favorite subjects, but, you know, biology, chemistry, physics, somehow, I, I, you know, I liked those four subjects together and. Yes. [01:57:43] Or so so so essentially, after a certain period of time, I wanted to actually back then it was a very popular sort of area of science called cybernetics. So it's sort of it's not really computer science, but it was like, you know, computational robotics. Yes. In this sense. And so I really wanted to to do that. And but then, you know, I you know, I realized that, you know, my biggest passion was in mathematics. [01:58:24] And later I you know, when, you know, studying in Moscow State University, I also realized that I really want to apply. [01:58:36] The the knowledge, so I really wanted to to mix, you know, the mathematical knowledge that I get with real life problems, and that could be you mentioned chemistry and biology and a sort of. [01:58:58] Does it make you sad, maybe I'm wrong on this, but it seems like. It's. Difficult to be in collaboration to do open big science in Russia. From my distant perspective and computer science, I don't I'm not I can go to conferences in Russia, I sadly don't have many collaborators in Russia. I don't know how many people doing great. I work in Russia. [01:59:27] Does it make does that make you sad? Am I wrong in seeing it this way? [01:59:32] Well, I mean, I am I have to tell you, I am I am privileged to to have collaborators in mathematics in Russia. And I think this is the informatic school in Russia is very strong. We have in Moscow, in Moscow, in Novosibirsk, in St Petersburg, we have great collaborators in Kazan. [01:59:59] And so at least, you know, in terms of, you know, my area of research, the strong people, there are strong people, a lot of great ideas, very open to collaboration. [02:00:15] So I perhaps, you know, it's my luck. [02:00:21] But, you know, I haven't experienced, you know, any difficulties in establishing collaborations that's been somatics. [02:00:32] It could be bad for matics to an area. It could be person by person related. But I just don't feel the warmth and love that I would. You know, you talk about the Seminole people who are French in artificial intelligence, France welcomes them with open arms in so many ways. I just don't feel the love from Russia. I do on the human beings, like people in general, like friends and and just cool, interesting people. But from the scientific community, no conferences, no big conferences. [02:01:06] And it's, uh. [02:01:08] Yeah, it's actually, you know, I, I'm trying to think, yeah, I cannot recall any any big AI conferences in Russia. It has an effect on for me, I haven't sadly been back to Russia, but my problem is it's very difficult. So now I have to renounce the citizenship. I was there. I mean, I'm a citizen of the United States and I make it very difficult. There's a mess now, right? [02:01:36] So, yeah, I want to be able to travel like, you know, legitimately. [02:01:43] Yeah. And it's not it's not an obvious process. They don't make it. So please. I mean, that's part of that. Like, you know, it should be super easy for me to travel there. [02:01:52] Well, you know, hopefully this unfortunate circumstances that we're in will actually promote the the remote collaborations. Yes. [02:02:06] And I think we we've just I think what we are experiencing right now is that you still can do science. You know, being Currington in your own homes, yeah, especially when it comes, I mean, you know, I certainly understand there is a very challenging time for experimental scientists and they have many collaborators who are, you know, who are affected by that. [02:02:29] But for computational scientists, yeah, we're really leaning into the remote communication. Nevertheless, I had to force you to talk to you in person because there's something that you just can't do in terms of conversation like this. I don't know why, but in person, it's very much needed. So I really appreciate you doing it. You have a collection of science bobbleheads. Yes. [02:02:53] Which look amazing. Which which bobblehead is your favorite and which real world version? Which scientist is your favorite? Yeah. [02:03:04] So, yeah, by the way, I was trying to bring it in but they are cranking now in my in my office they sort of demonstrate the social distance, so they're nicely spaced away from each other. [02:03:19] But so, you know, it's interesting. So I've been I've been collecting those bobbleheads for the past maybe 12 or 13 years. [02:03:28] And, you know, interestingly enough, it started with the two bobbleheads of Watson and Crick and. [02:03:39] Interestingly enough, my last bobblehead in this collection for now and my favorite one because I felt so good when I got it, was the Rosalind Franklin. And so so, you know, when I was the first group. [02:03:57] So I have Watson, Crick, Newton, Einstein, Marie Curie, Tesla. [02:04:06] Uh, of course, Charles Darwin, sort of Charles Darwin, um. And also, frankly, I am definitely missing quite a few of my favorite scientists and but so, you know, if. [02:04:25] I want to add to this collection, so I would add, of course, Komaroff and just that's that's that's you know, I've been always fascinated by. [02:04:40] His well, his dedication to science, but also his dedication to educating young people the next generation. [02:04:51] So it's it's it's very inspiring. [02:04:53] He's one of the well, OK. Yeah, he's one of Russia's greats. Yes. Yes. [02:04:59] So he also, you know, the school the high school that they attended was named after him and he was great, you know, so he founded the school school and he actually thought there is. [02:05:16] This is in Moscow. Yes. So but then I mean. You know, other people that I would definitely like to see in my collections was would be Alan Turing, would be John von Neumann. Yeah, you're a little bit later and the computer scientists, yes. Well, I mean, they don't they don't make them. I still am amazed they haven't made Alan Turing. Yeah. Yeah. Yes. And, um. And I would also add the Linus Pauling. [02:05:54] Linus Pauling. So his last point, so this is this is to me is one of the greatest chemists. And the person who actually discovered the secondary structure of proteins, who was very close to solving the DNA structure and now people argue about some of them were pretty sure that if not for this, you know, photograph 51 by Rosalind Franklin that, you know, Watson and Crick got access to, he would be you would be the one who would solve it. [02:06:45] Science is a funny race, it is. Let me ask the the biggest and the most ridiculous question. [02:06:52] So you've kind of studied the human body and its defenses and. These enemies that are about from a biological bioinformatics perspective, a computer scientist perspective, how is that made you see your own life, sort of the meaning of it, or just even seeing your what it means to be human? [02:07:21] Well, it certainly makes me realizing how fragile the human life is. If you think about this, a little tiny thing. Can impact the life of the whole humans kind. To such extent. So, you know, it's it's something to appreciate and to, you know. To remember that that, you know, we are fragile, we. Have to. Bond together as a society. And, you know. It also gives me sort of hope that what we do as scientists is useful. [02:08:22] Well, I don't think there's a better way to end. It means you take it so much for talking. [02:08:26] It is an honor, very much. Thanks for listening to that conversation with Demetri Cauchon and thank you to a presenting sponsor, Kashyap. Please consider supporting the podcast by downloading cash app and using Scolex podcast. If you enjoy this podcast, subscribe on YouTube review of Five Stars, an Apple podcast supported on page one. Or simply connect with me on Twitter, Àlex Friedman. And now let me leave you with some words from Edward Ausborn, Wilson, E.O. Wilson. [02:08:57] The variety of genes on the planet in viruses exceeds or is likely to exceed that in all of the rest of life combined. Thank you for listening and hope to see you next time.

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