定向进化模仿了整体的逐步调节
Andrew R Buller1,2, Paul van Roye2, Jackson K B Cahn3
1Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , United States.
Journal of the American Chemical Society
|May 2, 2018
概括
定向进化将三胺合成酶 (TrpB) 设计成一个独立的生物催化剂. 突变稳定了一个封闭的结构,使得有效的非正规氨基酸合成.
科学领域:
- 酵素学
- 蛋白质工程
- 生物催化
背景情况:
- 酸酶在生物催化中具有显著的催化潜力,但仍未得到充分利用.
- 酸合成酶 (TrpB) 是合成非正规氨基酸 (ncAA) 关键的一个模型酸酶.
- 之前的努力发展了PfTrpB用于独立的ncAA合成,但激活机制尚不清楚.
研究的目的:
- 阐明定向进化激活托合成酶 (PfTrpB) 的β子单元进行独立催化的机制.
- 了解突变如何改变催化循环和酶结构.
- 为了使各种各样的全酶成为独立的生物催化剂.
主要方法:
- 对Pyrococcus furiosus TrpB (PfTrpB) 的定向演化
- 酶变体的生化表征
- 多种化学状态的野生类型和进化PfTrpB的高分辨率晶体.
主要成果:
- 定向进化转移了限制速度的步骤,并有利于稳定,共价结合的酸添加物.
- 演化后的PfTrpB酶表现出模仿全激活的生物化学特性.
- 结构分析显示突变通过子域运动稳定闭合形状, 而不是局部变化.
- 晶体学提供了活跃PfTrpB中的第一个结构图.
结论:
- 定向进化可以在没有复杂模型的情况下重现各类效应,激活酶以实现独立功能.
- 大规模形态动态的稳定是激活PfTrpB的关键.
- 这项工作为将其他性酶改造为多功能独立生物催化剂铺平了道路.
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