生物缓冲区二碳酸盐/CO2增强了H2O2介导的蛋白质氨酸酸酶的失活
Haiying Zhou1, Harkewal Singh, Zachary D Parsons
1Department of Chemistry, University of Missouri, Columbia, Missouri 65211, United States.
Journal of the American Chemical Society
|September 15, 2011
概括
过氧化 (H2O2) 在体外缓慢地使蛋白氨酸酸酶 (PTPs) 不活化. 二碳酸盐/二氧化碳缓冲剂增强了H2O2的作用.
科学领域:
- 生物化学 生物化学
- 细胞信号传递 细胞信号传递
- 结构生物学 结构生物学
背景情况:
- 过氧化 (H2O2) 作为一个关键的细胞信号分子.
- H2O2通过氧化它们的催化氨酸残留物来使蛋白氨酸酸酶 (PTPs) 不活化.
- 通过H2O2无活化PTP在细胞信号传输中是快速的,但在体外是缓慢的.
研究的目的:
- 通过H2O2在体外和体内活体中对PTP无活化率的差异背后的机制进行调查.
- 为了识别可能导致 H2O2 介导 PTP 失活的因素.
- 阐明生物缓冲器在调节H2O2对PTPs的影响中的作用.
主要方法:
- 生物化学试验测量PTP活性和无活化动力学.
- 对PTP的高分辨率晶体分析.
- 在体外实验中使用不同度的过氧化和碳酸/CO2缓冲剂进行实验.
主要成果:
- 生物缓冲区二碳酸/CO2显著增强了通过H2O2.2.的PTP无活化.
- 在H2O2和二碳酸盐/CO2之间的反应产生过氧单碳酸盐.
- 结晶学数据支持一种机制,即过氧单碳酸盐氧化了PTPs的催化氨酸.
结论:
- 双碳酸盐/CO2缓冲剂通过过氧单碳酸盐的形成增强了H2O2诱导的PTP无活化.
- 这一发现解释了与体外条件相比,在细胞信号传输中观察到的更快的PTP无活化.
- 这项研究揭示了在生物系统中调节PTP活动的新机制.
相关概念视频
Bicarbonate-Carbonic Acid Buffer
The carbonic acid-bicarbonate buffer system is critical for maintaining the body's pH balance. It operates on the equilibrium:
Phosphate Buffer
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...
Protein Buffers in Blood Plasma and Cells
The human body utilizes protein buffer systems to maintain a stable pH. These systems capitalize on the dual role of amino acids, which can act as acids or bases by accepting or releasing hydrogen ions in response to pH changes. Protein buffer systems are particularly significant in the extracellular fluid (ECF) and intracellular fluid (ICF) of active cells, where structural and functional proteins provide substantial buffering capacity.
Certain amino acids can exist in a zwitterion state at a...
Certain amino acids can exist in a zwitterion state at a...
Buffer Systems in the Body
Chemical buffers play a critical role in the body's regulation of pH levels. These systems contain one or more compounds that stabilize pH changes by neutralizing strong acids or bases. When pH levels drop, hydrogen ions bind to a weak base; when pH levels rise, hydrogen ions are released. This dynamic process helps maintain pH within a narrow and stable range essential for normal physiological function.
A typical buffer system in bodily fluids includes a weak acid and its corresponding anion,...
A typical buffer system in bodily fluids includes a weak acid and its corresponding anion,...
Buffers
A solution containing appreciable amounts of a weak conjugate acid-base pair is called a buffer solution, or a buffer. Buffer solutions resist a change in pH when small amounts of a strong acid or a strong base are added. A solution of acetic acid and sodium acetate is an example of a buffer that consists of a weak acid and its salt: CH3COOH (aq) + CH3COONa (aq). An example of a buffer that consists of a weak base and its salt is a solution of ammonia and ammonium chloride: NH3 (aq) + NH4Cl...
Buffer Effectiveness
Buffer solutions do not have an unlimited capacity to keep the pH relatively constant . Instead, the ability of a buffer solution to resist changes in pH relies on the presence of appreciable amounts of its conjugate weak acid-base pair. When enough strong acid or base is added to substantially lower the concentration of either member of the buffer pair, the buffering action within the solution is compromised.
The buffer capacity is the amount of acid or base that can be added to a given volume...
The buffer capacity is the amount of acid or base that can be added to a given volume...

