研究揭示定向進化如何重塑酶的能量分布從而增強催化作用
作者：
小柯機器人發布時間：2020/11/22 23:35:24
定向進化如何重塑酶的能量分布以增強催化作用，這一成果由美國布蘭代斯大學Dorothee Kern和瑞士蘇黎世聯邦理工學院Donald Hilvert小組合作而取得。2020年11月19日出版的《科學》雜誌發表了這一研究成果。
將NMR、晶體學和停流技術應用於為基本質子轉移反應設計的酶，研究人員揭示了定向進化如何逐漸改變蛋白質支架的構象，從而形成一個狹窄的、高活性的構象合集，並將催化速率增加了近十億倍。
優化過程中獲得的突變可產生全局構象變化，包括高能主鏈重排、協同組織催化鹼和氧陰離子的穩定劑，從而完善了過渡態的穩定性。在設計過程中對構象亞狀態進行直接採樣，特別是穩定所有非生產構象的產能，可以加快用於許多蛋白質化學轉化催化劑的研發。
據介紹，由實驗室通過計算和優化產生的生物催化劑為探索增強催化功能的分子機制提供了可能。
附：英文原文
Title: How directed evolution reshapes the energy landscape in an enzyme to boost catalysis
Author: Renee Otten, Ricardo A. P. Pádua, H. Adrian Bunzel, Vy Nguyen, Warintra Pitsawong, MacKenzie Patterson, Shuo Sui, Sarah L. Perry, Aina E. Cohen, Donald Hilvert, Dorothee Kern
Issue&Volume: 2020/11/19
Abstract: The advent of biocatalysts designed computationally and optimized by laboratory evolution provides an opportunity to explore molecular strategies for augmenting catalytic function. Applying a suite of NMR, crystallographic, and stopped-flow techniques to an enzyme designed for an elementary proton transfer reaction, we show how directed evolution gradually altered the conformational ensemble of the protein scaffold to populate a narrow, highly active conformational ensemble and achieve a nearly billionfold rate acceleration. Mutations acquired during optimization enabled global conformational changes, including high-energy backbone rearrangements, that cooperatively organized the catalytic base and oxyanion stabilizer, thus perfecting transition-state stabilization. Explicit sampling of conformational sub-states during design, and specifically stabilizing productive over all unproductive conformations, could speed up the development of protein catalysts for many chemical transformations.
DOI: 10.1126/science.abd3623
Source: https://science.sciencemag.org/content/early/2020/11/18/science.abd3623
Science：《科學》，創刊於1880年。隸屬於美國科學促進會，最新IF：41.037