研究基质结合对西兰酶催化活性的影响
Lei Ma1, Guangqi Li2, Yunpeng Liu2
1College of Life Sciences and Engineering, Henan University of Urban Construction, Pingdingshan, 467000, Henan, People's Republic of China.
Applied microbiology and biotechnology
|September 16, 2023
概括
热友性西兰酶 (XynAF1) 的非催化氨基酸突变影响了基质结合和催化效率. 了解这些相互作用是酶工程的关键.
科学领域:
- 生物化学 生化学
- 酶学 是一种酶学.
- 结构生物学 结构生物学
背景情况:
- 克西兰酶是生物质降解的关键酶.
- 甘氨酸酸酶家族10 (GH10) 基氨酸酶是重要的工业酶.
- 非催化性氨基酸在西兰酶功能中的作用尚未完全理解.
研究的目的:
- 研究非催化性氨基酸N179和R246在来自Aspergillus fumigatus Z5.5.的热友性西兰酶XynAF1中的作用.
- 确定这些残留物中的突变如何影响基质结合和催化效率.
- 用X射线晶体学阐明这些效应的结构基础.
主要方法:
- 局部定向的突变发生产生XynAF1-N179S和XynAF1-R246K变体.
- 纯化野生类型和突变的西兰酶.
- 通过X射线衍射获得蛋白质产物复杂结构.
- 酶活性测定用于测量催化效率.
主要成果:
- 在N179和R246的突变通过减少分子间键,降低了亚基质结合能力.
- N179S突变增加了催化效率,而R246K和双突变N179S-R246K降低了它.
- 蛋白质结构显示最小的变化,表明影响主要是功能性的,而不是结构性的.
结论:
- 非催化性氨基酸N179和R246通过键促进基质结合.
- 改变这些残留物可以调节XynAF1.1的基质亲和力和催化效率.
- 酶基质结合能力直接影响酶的催化效率,为酶工程提供了洞察力.
相关概念视频
Enzymes
81.8K
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
81.8K
Introduction to Mechanisms of Enzyme Catalysis
8.3K
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...
8.3K
Introduction to Enzyme Kinetics
20.1K
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...
20.1K
Enzyme Kinetics
97.1K
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...
97.1K
Enzyme Inhibition
78.6K
Inhibitors are molecules that reduce enzyme activity by binding to the enzyme. In a normally functioning cell, enzymes are regulated by a variety of inhibitors. Drugs and other toxins can also inhibit enzymes. Some inhibitors bind to the enzyme’s active site, while others inhibit enzymatic activity by binding to other sites on the protein structure.
78.6K
Induced-fit Model
81.1K
Most chemical reactions in cells require enzymes—biological catalysts that speed up the reaction without being consumed or permanently changed. They reduce the activation energy needed to convert the reactants into products. Enzymes are proteins, that usually work by binding to a substrate—a reactant molecule that they act upon.
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical...
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical...
81.1K


