No Cover Image

Journal article 405 views

Microsomal glutathione transferase 1 exhibits one-third-of-the-sites-reactivity towards glutathione / William, Griffiths

Archives of Biochemistry and Biophysics, Volume: 487, Issue: 1, Pages: 42 - 48

Swansea University Author: William, Griffiths

Full text not available from this repository: check for access using links below.

Abstract

The trimeric membrane protein microsomal glutathione transferase 1 (MGST1) possesses glutathione transferase and peroxidase activity. Previous data indicated one active site/trimer whereas structural data suggests three GSH-binding sites. Here we have determined ligand interactions of MGST1 by sever...

Full description

Published in: Archives of Biochemistry and Biophysics
ISSN: 0003-9861
Published: 2009
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa10949
Tags: Add Tag
No Tags, Be the first to tag this record!
Abstract: The trimeric membrane protein microsomal glutathione transferase 1 (MGST1) possesses glutathione transferase and peroxidase activity. Previous data indicated one active site/trimer whereas structural data suggests three GSH-binding sites. Here we have determined ligand interactions of MGST1 by several techniques. Nanoelectrospray mass spectrometry of native MGST1 revealed binding of three GSH molecules/trimer and equilibrium dialysis showed three product molecules/trimer (Kd = 320 ± 50 μM). All three product molecules could be competed out with GSH. Reinvestigation of GSH-binding showed one high affinity site per trimer, consistent with earlier data. Using single turnover stopped flow kinetic measurements, Kd could be determined for a low affinity GSH-binding site (2.5 ± 0.5 mM). Thus we can reconcile previous observations and show here that MGST1 contains three active sites with different affinities for GSH and that only the high affinity site is catalytically competent.
College: Swansea University Medical School
Issue: 1
Start Page: 42
End Page: 48