SPECIFICITY AND FUNCTION OF ALCOHOL DEHYDROGENASES

描述：(改编自《调查员摘要》)总体目标 这项研究的目的是确定酒精脱氢酶的特异性 对于底物和抑制剂，阐明酶在 醇和羰基化合物的新陈代谢，并开发抑制试剂 可能与酒精中毒有关的特定底物的代谢。肝 酒精脱氢酶是酒精新陈代谢的限速因素，但 同工酶的组织分布、多样性及其广泛分布 底物的特性表明，这些酶不仅能氧化乙醇 而且还有各种各样的内源底物。此外，乙醇 氧化可能通过偶联反应加速羰基化合物的还原。 干扰其他底物新陈代谢的酶反应。这个 马E和S，小鼠A(1)和C(4)，以及人阿尔法的特异性， 不同底物上的β1、γ2、pi和sigma酶将由 稳态动力学和暂态动力学。酶和速率的作用机制 将确定每个步骤的常量，以便可以 与结合和催化相关。酶的非竞争性抑制剂 将被开发，以便更好地定义特异性并防止 甲醇或乙二醇的代谢以及可能对其有贡献的化合物 为了酗酒。选定络合物的三维结构将被 由X射线结晶学确定，以确认和扩展模型 用于预测特异度的活动站点拓扑。动力学参数 在体外测定将被用来模拟酒精的代谢和 小鼠和人体内的羰基化合物，以及耦合交换的速率将 被模拟以评估酶的改变能力 体内的代谢状态。

DESCRIPTION: (Adapted from the Investigator's Abstract) The overall objectives of this research are to determine the specificities of alcohol dehydrogenases for substrates and inhibitors, to elucidate the functions of the enzymes in the metabolism of alcohols and carbonyl compounds, and to develop agents to inhibit metabolism of particular substrates that might be involved in alcoholism. Liver alcohol dehydrogenase is a rate-limiting factor in alcohol metabolism, but the tissue distribution and multiplicity of isoenzymes and their broad specificities for substrates suggest that the enzymes oxidize not only ethanol but also a great variety of endogenous substrates. Furthermore, ethanol oxidation may accelerate the reduction of carbonyl compounds by a coupled enzymatic reaction that disturbs metabolism of other substrates. The specificities of the horse E and S, mouse A (1) and C(4), and the human alpha, beta 1, gamma 2, pi and sigma enzymes on various substrates will be defined by steady-state and transient kinetics. The mechanisms of the enzymes and the rate constants for each step will be determined, so that specificity data can be correlated with binding and catalysis. Uncompetitive inhibitors of the enzymes will be developed in order to better define specificity and to prevent metabolism of methanol or ethylene glycol and compounds that might contribute to alcoholism. Three-dimensional structures of selected complexes will be determined by x-ray crystallography in order to confirm and extend models of active site topologies for prediction of specificities. The kinetic parameters determined in vitro will be used to simulate metabolism of alcohols and carbonyl compounds in mice and men, and the rates of the coupled exchange will be simulated in order to assess the capabilities of the enzymes to alter metabolic states in vivo.