酸单二水解的竞争机制
Fernanda Duarte1, Alexandre Barrozo1, Johan Åqvist1
1Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University , BMC Box 596, SE-751 24 Uppsala, Sweden.
Journal of the American Chemical Society
|July 30, 2016
概括
酸单水解机制取决于离开的组. 良好的脱离组倾向于溶剂辅助的途径,而差的脱离组则会产生机械的模糊性,影响生物催化.
科学领域:
- 生物化学
- 计算化学
- 物理化学
背景情况:
- 单水解在生物系统中至关重要.
- 机理细节,特别是离开组pKa的作用,仍然不清楚.
- 了解这些反应有助于酶催化和药物设计.
研究的目的:
- 调查离开组pKa对酸单水解通路的影响.
- 阐明溶剂辅助和基质辅助机制之间的竞争.
- 建立这些反应的线性自由能量关系.
主要方法:
- 计算电子结构研究.
- 甲基酸盐和替代酸单的比较分析
- 线性自由能量关系结构.
主要成果:
- 水解机制是由离开组的性质决定的.
- 优秀的离开群体更喜欢分离的溶剂辅助路径.
- 离开组pKa的增加减少了路径能量差异,导致离开组的机制模两可.
结论:
- 过渡状态变化平稳, 保持离散的路径.
- 生物催化剂面临更高的障碍 基质辅助途径与良好的离开组.
- 由于消除了内在偏好, 致使穷人离开群体的催化剂偏好发生了变化.
相关概念视频
Hydrolysis of ATP
82.9K
The bonds of adenosine triphosphate (ATP) can be broken through the addition of water, releasing one or two phosphate groups in an exergonic process called hydrolysis. This reaction liberates the energy in the bonds for use in the cell—for instance, to synthesize proteins from amino acids.
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine...
If one phosphate group is removed, a molecule of ADP—adenosine diphosphate—remains, along with inorganic phosphate. ADP can be further hydrolyzed to AMP—adenosine...
82.9K
Hydrolysis of ATP
8.1K
8.1K
Phosphodiester Linkages
113.4K
Overview
Phosphodiester bond forms when a phosphoric acid molecule (H3PO4) links with two hydroxyl groups (–OH) of two other molecules, forming two ester bonds. Two water molecules are released in this process. The phosphodiester bond is commonly found in nucleic acids (DNA and RNA) and plays a critical role in their structure and function.
Phosphodiester Bonds Link Nucleotides Together
DNA and RNA are polynucleotides or long chains of nucleotides that are linked together. A nucleotide is...
Phosphodiester bond forms when a phosphoric acid molecule (H3PO4) links with two hydroxyl groups (–OH) of two other molecules, forming two ester bonds. Two water molecules are released in this process. The phosphodiester bond is commonly found in nucleic acids (DNA and RNA) and plays a critical role in their structure and function.
Phosphodiester Bonds Link Nucleotides Together
DNA and RNA are polynucleotides or long chains of nucleotides that are linked together. A nucleotide is...
113.4K
Phosphate Buffer
5.9K
The phosphate buffer system is a critical biological mechanism for maintaining pH stability in the body. This system operates primarily through two components: sodium dihydrogen phosphate (NaH2PO4), which acts as a weak acid, and sodium hydrogen phosphate (Na2HPO4), which serves as a weak base.
Sodium dihydrogen phosphate does not fully dissociate in neutral or acidic solutions. When a strong base, such as sodium hydroxide (NaOH), is introduced into the solution, sodium dihydrogen phosphate...
Sodium dihydrogen phosphate does not fully dissociate in neutral or acidic solutions. When a strong base, such as sodium hydroxide (NaOH), is introduced into the solution, sodium dihydrogen phosphate...
5.9K
Protein Kinases and Phosphatases
15.4K
Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
15.4K
ATP Driven Pumps I: An Overview
10.3K
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...
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...
10.3K


