在酶反应轨迹上的内在运动
Katherine A Henzler-Wildman1, Vu Thai, Ming Lei
1Department of Biochemistry and Howard Hughes Medical Institute, Brandeis University, Waltham, Massachusetts 02454, USA.
Nature
|November 21, 2007
概括
酶使用特定的形状变化来实现催化. 腺酸酶酶的动力学揭示了通往催化活性状态的首选途径,指导了酶的功能.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 酶学 是一种酶学.
背景情况:
- 酶通过基质结合和形状变化加速生化反应.
- 了解酶如何达到它们的催化能力状态对于阐明酶机制至关重要.
- 腺酸酶是一种模型酶,用于研究构造动力学和催化.
研究的目的:
- 为了研究无连接体腺酸激酶的结构亚态和动态路径.
- 为酶构造变化提供晶体学和计算证据.
- 了解酶结构如何促进有效的催化.
主要方法:
- 采用X射线晶体学来捕获形状子状态.
- 分子动力学模拟以建模酶动力学.
- 核磁共振 (NMR) 和单分子光共振能量转移 (smFRET) 用于研究运动的时间尺度.
主要成果:
- 结晶学证据显示,在无配体腺酸酶中存在构造基态.
- 分子动力学模拟显示在纳秒时间尺度上采样的部分闭合构造.
- 核磁共振和smFRET揭示了微秒到毫秒时间尺度上完全封闭的,具有催化能力的状态的罕见采样.
结论:
- 没有基质的腺酸激酶表现出朝着一种催化能力状态的定向构造运动.
- 这些首选途径与酶的折叠固有,可能是酶催化过程中的一般原则.
- 酶结构决定了动态路径,优化了酶的化学反应.
更多相关视频
09:38Dissecting Mechanoenzymatic Properties of Processive Myosins with Ultrafast Force-Clamp Spectroscopy
Published on: July 1, 2021
09:17Structure-Based Simulation and Sampling of Transcription Factor Protein Movements along DNA from Atomic-Scale Stepping to Coarse-Grained Diffusion
Published on: March 1, 2022
相关概念视频
Introduction to Enzyme Kinetics
Enzyme kinetics studies the rates of biochemical reactions. Scientists monitor the reaction rates for a particular enzymatic reaction at various substrate concentrations. Additional trials with inhibitors or other molecules that affect the reaction rate may also be performed.
The experimenter can then plot the initial reaction rate or velocity (Vo) of a given trial against the substrate concentration ([S]) to obtain a graph of the reaction properties. For many enzymatic reactions involving a...
The experimenter can then plot the initial reaction rate or velocity (Vo) of a given trial against the substrate concentration ([S]) to obtain a graph of the reaction properties. For many enzymatic reactions involving a...
Enzyme Kinetics
Enzymes speed up reactions by lowering the activation energy of the reactants. The speed at which the enzyme turns reactants into products is called the rate of reaction. Several factors impact the rate of reaction, including the number of available reactants. Enzyme kinetics is the study of how an enzyme changes the rate of a reaction.
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
Introduction to Mechanisms of Enzyme Catalysis
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...
Introduction to Mechanisms of Enzyme Catalysis
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...
Mechanical Protein Functions
Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force.
