酵母谷胱甘肽还原酶逆反应的“分支”机制。根据稳态动力学数据估算酶的标准电位值。

A 'branched' mechanism of the reverse reaction of yeast glutathione reductase. An estimation of the enzyme standard potential values from the steady-state kinetics data.

作者信息

Rakauskiene G A, Cenas N K, Kulys J J

机构信息

Institute of Biochemistry, Academy of Sciences Lithuanian SSR, Mokslininku, USSR.

出版信息

FEBS Lett. 1989 Jan 16;243(1):33-6. doi: 10.1016/0014-5793(89)81212-8.

DOI:10.1016/0014-5793(89)81212-8

PMID:2646147

Abstract

The reduced glutathione-linked NADP+ reduction, catalyzed by yeast glutathione reductase, follows a 'sequential' or 'ping-pong' mechanism at high or low NADP+ concentrations, respectively. The pattern of the NADPH and NADP+ cross-inhibition reflects not only the competition for the binding site, but the shift of the reaction equilibrium as well. A 'branched' scheme of the glutathione reductase reaction is presented. The enzyme standard potential (-255 mV, pH 7.0) was estimated from the ratio of the NADPH and NADP+ rate constants corresponding to the ping-pong mechanism.

摘要

由酵母谷胱甘肽还原酶催化的、与还原型谷胱甘肽相关的NADP⁺还原反应，在高或低NADP⁺浓度下分别遵循“有序”或“乒乓”机制。NADPH和NADP⁺交叉抑制的模式不仅反映了对结合位点的竞争，还反映了反应平衡的移动。本文提出了谷胱甘肽还原酶反应的“分支”方案。根据对应于乒乓机制的NADPH和NADP⁺速率常数的比率，估算出该酶的标准电位（-255 mV，pH 7.0）。