谷胱甘肽的立体异构体：制备与酶活性

Stereoisomers of glutathione: preparation and enzymatic reactivities.

作者信息

Oikawa T, Yamauchi T, Kumagai H, Soda K

机构信息

Department of Biotechnology, Faculty of Engineering, Kansai University, Osaka, Japan.

出版信息

J Nutr Sci Vitaminol (Tokyo). 1999 Apr;45(2):223-9. doi: 10.3177/jnsv.45.223.

DOI:10.3177/jnsv.45.223

PMID:10450563

Abstract

We synthesized a series of stereoisomers of glutathione (GSH) and glutathione disulfide (GSSG) by the solid-phase method. These peptides were used to examine their reactivities with enzymes acting on glutathione. The glutathione reductase of yeast acted only on LL-GSSG. Glutathione S-transferase catalyzed the conjugation of 1-chloro-2,4-dinitrobenzene with LL-GSH and DL-GSH (Km (mM): for LL-GSH, 0.035; and for DL-GSH, 0.62), but the DD- and LD-diastereomers were inert. gamma-Glutamyl transpeptidase catalyzed the transfer of gamma-glutamyl moiety of LL-GSH and DL-GSH to taurine forming gamma-glutamyl taurine and cysteinyl taurine (Km (mM): for LL-GSH, 0.336; and for DL-GSH, 0.628), but the other diastereomers were not the substrates. The occurrence of L-cysteinyl residue in the tripeptides is required for the glutathione analogue to be a substrate of the enzymes.

摘要

我们通过固相法合成了一系列谷胱甘肽（GSH）和谷胱甘肽二硫化物（GSSG）的立体异构体。这些肽被用于检测它们与作用于谷胱甘肽的酶的反应活性。酵母中的谷胱甘肽还原酶仅作用于LL-GSSG。谷胱甘肽S-转移酶催化1-氯-2,4-二硝基苯与LL-GSH和DL-GSH的结合（Km（mM）：LL-GSH为0.035；DL-GSH为0.62），但DD-和LD-非对映异构体无活性。γ-谷氨酰转肽酶催化LL-GSH和DL-GSH的γ-谷氨酰部分转移至牛磺酸，形成γ-谷氨酰牛磺酸和半胱氨酰牛磺酸（Km（mM）：LL-GSH为0.336；DL-GSH为0.628），但其他非对映异构体不是底物。谷胱甘肽类似物要成为酶的底物，三肽中必须存在L-半胱氨酰残基。