模型金属蛋白中的多电子化学:对乙-CoA合成的机制影响
Anastasia C Manesis1, Matthew J O'Connor1, Camille R Schneider1
1The Ohio State University , 100 West 18th Avenue, Newman & Wolfrom Laboratory of Chemistry, Columbus, Ohio 43210, United States.
Journal of the American Chemical Society
|July 6, 2017
概括
研究人员开发了一种替代的青蛋白 (NiAz) 来模拟乙辅酶A合成酶 (ACS). 这种NiAz模型模仿了ACS活动,提供了对关键有机金属催化机制的见解.
科学领域:
- 生物化学和生物有机化学
- 酶机制和建模
- 有机金属催化
背景情况:
- 乙辅酶A合成酶 (ACS) 对于无氧代谢至关重要,通过依赖的有机金属中间体催化乙-CoA合成.
- 原生ACS酶的复杂性阻碍了对其催化机制的全面了解.
- 了解ACS对于开发用于有机金属反应的新生物催化剂至关重要.
研究的目的:
- 开发一种基于蛋白质的辅因子 (NiP) 合成酶的功能模型.
- 通过使用简化,明确的模型系统来研究ACS的催化机制.
- 探索复杂的有机金属过程中的工程生物催化剂的潜力.
主要方法:
- 创建一个替代的青蛋白 (NiAz) 作为NiP中心的模型.
- 描述NiAz的氧化还原特性,证明其进入NiI,NiII和NiIII的氧化状态.
- 对NiAz与CO和甲基结合的光谱和计算分析,以及NiI-CO物种的表征.
主要成果:
- NiAz是第一个含的蛋白质模型,能够在生理潜力范围内进入三种氧化状态.
- NiAz对CO和甲基具有生物学相关的结合亲缘关系.
- 光谱和计算数据显示NiAz模型与原生ACS酶之间存在相似之处,特别是对于NiI-CO中间体.
结论:
- NiAz模型成功地模仿了乙辅酶A活性和反应性的关键方面.
- 这项研究为ACS所使用的有机金属机制提供了宝贵的见解.
- 开发的NiAz系统对未来的有机金属转化生物催化剂工程具有前景.
相关概念视频
Catalysis
31.0K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
31.0K
Introduction to Mechanisms of Enzyme Catalysis
11.0K
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...
11.0K
Allosteric Proteins-ATCase
6.7K
Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
6.7K
Cooperative Allosteric Transitions
9.1K
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
9.1K
Cofactors and Coenzymes
13.0K
Enzymes are proteins made of amino acids. The functional group of each constituent amino acid catalyzes a wide variety of chemical reactions via ionic interactions or acid-base reactions. However, amino acids cannot catalyze oxidation-reduction and group transfer reactions and need to be aided by non-protein components called cofactors. Cofactors are also referred to as the chemical teeth of an enzyme.
Cofactors can be metallic ions or organic molecules called coenzymes. These types of helper...
Cofactors can be metallic ions or organic molecules called coenzymes. These types of helper...
13.0K
Ligand Binding and Linkage
5.7K
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence...
5.7K


![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)