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氨酸激酶激活氨酸通过金字塔化和极化酸化

Fabio Falcioni^1,2, Robert W Molt³, Yi Jin^1,2

¹Department of Chemistry, University of Manchester, Manchester M13 9PL, U.K.

ACS catalysis

|May 9, 2024

概括

氨酸激酶 (AK) 使用键网络来扭曲氨酸,从而实现高效的转移. 这种机制促进了前向和逆向反应,这对于生物学上对氨酸的修饰至关重要.

科学领域:

生物化学生物化学
计算化学的计算化学
酶学是一种酶学.

背景情况:

酸化氨酸是一种重要的生物过程.
氨酸激酶 (AK) 促进基从ATP转移到氨酸.
了解AK的机制是理解生物学中的氨酸修饰的关键.

研究的目的:

使用密度函数理论 (DFT) 阐明AK催化反应的过渡状态 (TS) 模型.
调查结在AK的催化机制中的结的作用.
了解逆反应的机制,包括酸的解.

主要方法:

用密度函数理论 (DFT) 的计算来建模AK催化反应的过渡状态.
分析键网络及其对基质构成和电子性质的影响.
在催化过程中对 arginine 侧链的电子和结构变化的研究.

主要成果:

开发了AK催化氨酸酸化的详细过渡状态模型.
鉴定出一个由50多个键组成的网络,诱导了阿尔金因瓜尼尼 (Nη2) 的显著金字塔化和极化.
这种扭曲使Nη2电子密度与裂变的P-O键对齐,通过关联机制促进线性酸转移. 反向反应涉及基质扭曲,以增强Nη2的基本性,用于质子化和随后的ATP再生.

结论:

该研究揭示了一种新的机制,涉及在酶催化过程中在阿金氨酸侧链中极化-金字塔化.
这种机制很可能在参与阿金氨酸翻译后修饰的各种酶中得到保留.
这些发现提供了对生物系统中高效酸转移的能量和结构要求的基本见解.

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