谷氨酸脱碳酶的pH适应性进化使得可以在没有pH控制的情况下进行胺黄油酸生物合成
Chenshuo Song1, Jie Luo2, Jun Qiao3
1Key Laboratory of Industrial Biotechnology (Ministry of Education), School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China.
Bioresource technology
|October 3, 2025
概括
设计了一种用于生产氨酸 (GABA) 的酶,以在中性pH下工作,大大降低成本和环境影响,以实现可持续生产.
科学领域:
- 生物催化和酶工程 生物催化和酶工程
- 代谢工程是代谢工程.
- 计算化学的计算化学
背景情况:
- 谷氨酸脱碳酶 (GAD) 的活性依赖于pH值,需要酸消耗才能产生胺黄油酸 (GABA).
- 这种pH依赖性增加了生产成本和环境影响.
- 为中性pH活性设计GAD对于可持续的GABA生物合成至关重要.
研究的目的:
- 为了设计来自大肠杆菌 (EcGadB) 的谷氨酸脱碳酶,以在中性pH下增强活性.
- 开发一个强大的和可持续的GABA生产的酶过程.
- 为酶工程建立一个集成的计算和定向进化方法.
主要方法:
- 恒定pH分子动力学 (CpHMD) 模拟以准pH敏感的γ-carboxyl结合环 (γ-CBL).
- 适应性代进化 (AIE) 由GABA生物传感器指导,用于酶工程.
- 用高斯加速分子动力学 (GaMD) 模拟来理解形状稳定.
主要成果:
- 工程突变M3 (Y51L/A56P/D68N/D69T) 在pH值7.5.5时,催化效率增加了43.5倍.
- 突变M4表现出增强的热稳定性,并应用于无pH控制的系统.
- 获得高GABA产量:360g/L (酶),219g/L (全细胞) 和60g/L (发酵).
结论:
- 通过消除pH控制,工程 EcGadB 变种能够实现高效和可持续的 GABA 生产.
- 集成的计算/定向进化策略是有效的酶工程.
- 这种方法为工业GABA生产提供了一个经济可行的途径.
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