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

FEBS Letters

Kulys, Juozas J.¹  Rakauskien≐, Gelm≐ A.¹  Č≐nas, Narimantas K.¹ 

[1] Institute of Biochemistry, Academy of Sciences Lithuanian SSR, Vilnius 232021, Mokslininku 12, USSR

关键词: Glutathione reductase;    Steady-state kinetics;    Redox potential;    GSSG;    oxidized glutathione;    GSH;    reduced glutathione;    E°;    standard potential;    TN;    turnover number;    TN/K m;    bimolecular rate constant;    Eo;    oxidized enzyme;    Er;    reduced enzyme;    DTT;    dithiothreitol;   

DOI  :  10.1016/0014-5793(89)81212-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown