Mondal M S, Mitra S
Chemical Physics Group, Tata Institute of Fundamental Research, Bombay, India.
Biochemistry. 1994 Aug 30;33(34):10305-12. doi: 10.1021/bi00200a010.
The kinetics and thermodynamics of the reductive half-reaction of xanthine oxidase with xanthine as substrate have been investigated by stopped-flow kinetic measurements. The temperature dependence of the steady-state and transient kinetics of the reductive half-reaction reveals the existence of at least three molecular intermediates during this half-reaction. All the microscopic rate constants and the thermodynamic activation parameters of the elementary steps of the reductive half-reaction have been determined for the first time. The microscopic rate constants and the thermodynamic activation parameters of the individual steps show wide variations in their magnitudes. The present work provides the most detailed and incisive description of the reaction of xanthine oxidase with its physiological substrate xanthine.
通过停流动力学测量研究了以黄嘌呤为底物时黄嘌呤氧化酶还原半反应的动力学和热力学。还原半反应的稳态和瞬态动力学的温度依赖性揭示了在该半反应过程中至少存在三种分子中间体。首次确定了还原半反应基本步骤的所有微观速率常数和热力学活化参数。各个步骤的微观速率常数和热力学活化参数在大小上有很大差异。本工作对黄嘌呤氧化酶与其生理底物黄嘌呤的反应提供了最详细和深刻的描述。
