相关实验视频
Updated: Jul 16, 2026

09:58
Light-driven Enzymatic Decarboxylation
Published on: May 22, 2016
乙烯基-CoA合成酶/一氧化碳脱酶被铜无活化
Matthew R Bramlett1, Xiangshi Tan, Paul A Lindahl
1Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, USA.
Journal of the American Chemical Society
|August 2, 2003
概括
铜对于乙-CoA合成酶 (ACS) 催化是不必要的. 相反,铜通过与活性部位结合来使ACS无活化,防止关键的甲基组转移并阻断关键的光谱信号.
科学领域:
- 生物化学 生物化学
- 酶催化酶的催化作用
- 生物有机化学 生物有机化学
背景情况:
- 来自Moorella thermoacetica的乙-CoA合成酶 (ACS) 的最近的晶体结构揭示了不同的活性位点 (A-集群) 金属组成和几何形状.
- 这些结构变化促使人们提出了两种不同的催化机制的建议:一种是基于的,另一种是基于铜的.
研究的目的:
- 调查铜在乙烯基-CoA合成酶 (ACS) 活性和机制中的作用.
- 为了确定铜是否需要催化,或者它是否起到抑制作用.
主要方法:
- 酶试验测量合成酶和甲基转移活性.
- 分析净化ACS中的金属含量.
- 电子偏磁共振 (EPR) 谱学,包括经过CO处理的样本.
主要成果:
- 铜不需要用于乙-CoA合成酶 (ACS) 催化.
- 铜通过与A集群的近位点结合来使ACS失活.
- 铜结合防止甲基组从电铁硫蛋白中被接受,并阻断了特有的NiFeC EPR信号.
结论:
- 对ACS提出的基于铜的催化机制不太可能.
- 铜作为ACS的抑制剂,干扰基质结合和催化周转.
- 支持基于Ni的机制,铜被确定为有害污染物.
相关概念视频
Pyruvate Oxidation
After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...
Oxidative Cleavage of Alkenes: Ozonolysis
In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.
Fates of Pyruvate
Pyruvate is the end product of glycolysis, where glucose is oxidized to pyruvate, simultaneously reducing NAD+ to NADH. Two molecules of ATP are also produced by substrate-level phosphorylation.
In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...
In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...
Loss of Carboxy Group as CO2: Decarboxylation of β-Ketoacids
Carboxylic acids, upon heating, undergo a decarboxylation reaction by releasing carbon dioxide gas. Monocarboxylic acids do not undergo decarboxylation easily. However, a silver salt of carboxylic acid reacts with bromine or iodine under high temperature to release carbon dioxide gas and forms halide with one less carbon. This reaction is called the Hunsdiecker reaction.
Phase I Oxidative Reactions: Overview
Phase I biotransformation, or functionalization, is a crucial chemical process that converts drugs and other xenobiotics into more water-soluble forms, facilitating expulsion from the body. It involves oxidative, reductive, and hydrolytic reactions that add or unveil polar functional groups on lipophilic substrates. Key players in phase I reactions are the mixed-function oxidases. Situated in liver cell microsomes, these enzymes predominantly carry out drug metabolism. They require molecular...
Respiration Pathways
Cellular respiration is a fundamental metabolic process that enables organisms to generate energy from organic molecules. One of its central pathways is the tricarboxylic acid (TCA) cycle, also known as the Krebs cycle, which plays a crucial role in energy production and biosynthetic processes.Conversion of Pyruvate to Acetyl-CoAThe pyruvate generated from glycolysis undergoes oxidative decarboxylation by the pyruvate dehydrogenase complex, producing acetyl-CoA, one molecule of NADH, and one...

