Gruys K J, Gregory P R, Schuster S M
J Inorg Biochem. 1986 Sep;28(1):67-77. doi: 10.1016/0162-0134(86)80024-1.
The rates of the conformational isomerization reaction of the diastereomers of beta,gamma-bidentate CrATP were studied as a function of pH, buffer concentration, ionic strength, and temperature. The progress of the reaction was monitored by quenching the reaction at various times, and then isolating the individual diastereomers and quantitating the percent of each. This was accomplished using the reverse-phase high-performance liquid chromatography separation technique developed in this laboratory [K. J. Gruys, and S. M. Schuster, Anal. Biochem. 125, 66-73 (1982)]. The rate constants for this isomerization were then determined by obtaining the best computer fit of the data to a reversible binary mechanism (i.e., A in equilibrium B) using interative descent methods. The reaction rate was shown to be dependent on pH, temperature, and ionic strength, but independent of buffer concentration. Keq. constants were independent of all variables except ionic strength. The results from this study are interpreted in terms of a reaction mechanism involving a preequilibrium ionization of the diastereomers followed by a rate-limiting interconversion process.
研究了β,γ-双齿型CrATP非对映异构体的构象异构化反应速率与pH值、缓冲液浓度、离子强度和温度的关系。通过在不同时间淬灭反应，然后分离各个非对映异构体并定量每种异构体的百分比来监测反应进程。这是使用本实验室开发的反相高效液相色谱分离技术完成的[K. J. Gruys和S. M. Schuster，《分析生物化学》125, 66 - 73(1982)]。然后通过使用迭代下降法将数据与可逆二元机制（即A⇌B）进行最佳计算机拟合来确定该异构化的速率常数。结果表明反应速率取决于pH值、温度和离子强度，但与缓冲液浓度无关。平衡常数Keq除离子强度外与所有变量无关。本研究结果根据一个反应机理进行解释，该机理涉及非对映异构体的预平衡电离，随后是限速互变过程。
