平衡动力和热力学控制:由烯环酶进行碳酸循环的机制
1Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Journal of the American Chemical Society
|October 16, 2003
概括
斯夸伦-霍环酶 (SHC) 使用一个QM/MM潜力来模拟碳酸循环. 动力控制决定了产品的分布,有利于在其他途径上形成类.
科学领域:
- 生物化学 生物化学
- 计算化学计算化学
- 酶学 是一种酶学.
背景情况:
- 斯夸伦-霍环酶 (SHC) 催化了一种复杂的循环反应.
- 在生物化学中,了解霍胺生物合成的机制至关重要.
研究的目的:
- 调查烯到烯循环的分子动力学.
- 阐明SHC内部的碳酸循环化机制.
- 确定控制产品分配的因素.
主要方法:
- 量子力学和分子力学 (QM/MM) 的联合潜力.
- 自由能源模拟和自由能源表面建设.
- 分子动力学模拟.分子动力学模拟.
主要成果:
- 碳酸循环级联涉及热力学和动力学控制的平衡.
- 五到六个成员的环扩张不是C或D环形成的可行途径.
- 两个异步协同的路径起源于A/B双循环环基离子中间体.
- 这些途径导致了不同的四环和五环霍帕诺伊德骨.
结论:
- 产品分布在野生类型的SHC受动控制.
- 五环形霍帕诺酸的99%的产量是由动力有利性解释的.
- 该机制强调了对复杂的自然产品生物合成的复杂控制.
相关概念视频
ATP Driven Pumps I: An Overview
ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient.
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...
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...
Regulation of Metabolism
Cellular needs and conditions vary from cell to cell and change within individual cells over time. For example, the required enzymes and energetic demands of stomach cells are different from those of fat storage cells, skin cells, blood cells, and nerve cells. Furthermore, a digestive cell works much harder to process and break down nutrients during the time that closely follows a meal compared with many hours after a meal. As these cellular demands and conditions vary, so do the amounts and...
Non-equilibrium in the Cell
An important concept in studying metabolism and energy is that of chemical equilibrium. Most chemical reactions are reversible. They can proceed in both directions, releasing energy into their environment in one direction, and absorbing it from the environment in the other direction. The same is true for the chemical reactions involved in cell metabolism, such as the breaking down and building up of proteins into and from individual amino acids, respectively. Reactants within a closed system...
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...
Bioreactor Controls-I
Maintaining optimal conditions within fermenters is essential for maximizing microbial productivity and ensuring process efficiency. This lesson focuses on key parameters—temperature, foam, pH, carbon dioxide, oxygen, and pressure—and their precise measurement and control strategies in fermentation systems.Temperature ControlTemperature regulation is critical due to the exothermic nature of many fermentation processes. In small laboratory fermenters, temperature is commonly monitored using...


