Faculty Collaboration Database

S-Nitrosoglutathione as a substrate for gamma-glutamyl transpeptidase. Biochem J 1997 Apr 15;323 ( Pt 2)(Pt 2):477-81

Date

04/15/1997

Pubmed ID

9163341

Pubmed Central ID

PMC1218344

DOI

10.1042/bj3230477

Scopus ID

2-s2.0-0030945376 (requires institutional sign-in at Scopus site)   122 Citations

Abstract

S-Nitrosoglutathione (GSNO) has been used as a nitric oxide (.NO) donor compound and has also been postulated to be involved in the transport of .NO in vivo. In this study we have examined the possibility that GSNO is a substrate for gamma-glutamyl transpeptidase (gamma-GT), an enzyme that hydrolyses the gamma-glutamyl moiety of glutathione to give glutamate and cysteinylglycine. gamma-GT accelerated the decomposition of GSNO, forming S-nitrosocysteinylglycine (CG-SNO) by a mechanism inhibitable by the gamma-GT inhibitors acivicin and S-methylglutathione. The Km of gamma-GT for GSNO was found to be 28 microM. In the presence of contaminating transition metal ions, gamma-GT accelerated the release of ;NO from GSNO, as CG-SNO is more susceptible to transition metal ion-dependent decomposition than GSNO. However, in the presence of the transition metal ion chelator diethylenetriaminepentaacetic acid, neither GSNO nor CG-SNO decomposed to generate .NO. Neither S-methylglutathione nor acivicin affected the vasodilatory response to GSNO in an isolated perfused rat heart. However, rat kidney homogenate stimulated the decomposition of GSNO by an acivicin-inhibitable mechanism. It is likely therefore that gamma-GT is involved in the decomposition of GSNO in the kidney but not in the heart.

Author List

Hogg N, Singh RJ, Konorev E, Joseph J, Kalyanaraman B

Authors

Neil Hogg PhD Associate Dean, Professor in the Biophysics department at Medical College of Wisconsin
Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Coronary Circulation
Electron Spin Resonance Spectroscopy
Glutathione
In Vitro Techniques
Kidney
Kinetics
Male
Nitroso Compounds
Platelet Aggregation Inhibitors
Rats
Rats, Sprague-Dawley
S-Nitrosoglutathione
Vasodilation
gamma-Glutamyltransferase