在人类二氧化碳无水酶II中,质子运输机制的解
C Mark Maupin1, Robert McKenna, David N Silverman
1Center for Biophysical Modeling and Simulation and Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA.
人类碳酸无水酶II使用水集群进行质子运输,这对其快速的酶活性至关重要. 希斯64的方向和水群稳定性显著影响了这个速度限制的步骤.
科学领域:
- 生物化学 生物化学
- 酶学 是一种酶学.
- 计算化学的计算化学
背景情况:
- 人类碳酸无水酶II (HCA II) 是一种高效的酶.
- 它的催化机制涉及一个限制速率的质子传输 (PT) 阶段.
- 了解这个PT步骤是酶功能的关键.
研究的目的:
- 调查HCA II中质子运输事件的原子细节.
- 评估活动地点水集群的作用和His64在PT的方向.
- 阐明控制速度限制步骤的因素.
主要方法:
- 多状态实证价值键 (MS-EVB) 计算方法.
- 质子运输的原子层次模拟.
- 对不同 His64 导向的自由能源障碍的分析.
主要成果:
- 在HCA II中,用于质子运输的水集群是暂时活跃的.
- 在结水/氧化物和His64.4之间发生了质子转移.
- PT取决于水集群的形成和His64的方向.
- 他的64方向直接影响PT自由能量屏障.
- 在没有His64相互作用的情况下,确定了三种不同的质子入出路径.
结论:
- 活动地点的水集群和His64的方向对于HCA II的质子传输效率至关重要.
- 速度限制步骤可以在质子转移到His64和His64去/质子化之间转移.
- 结果提供了对酶-水接口和HCA II突变体研究的见解.
更多相关视频
07:38Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane
Published on: March 30, 2015
12:48Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays
Published on: February 19, 2013
相关概念视频
ATP Driven Pumps I: An Overview
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
ATP Driven Pumps III: V-type Pumps
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
Chemiosmosis and ATP Synthesis
Electron Transport Chain: Complex III and IV
Chemiosmosis
Electron Transport Chain
The electron transport chain involves a series of protein complexes on the inner mitochondrial membrane that undergo a series of redox reactions. At the end of this chain, the electrons reduce...
ATP Synthase: Mechanism
