Stereoselective conjugation of a uricosuric diuretic with glutathione by glutathione transferase 3-3

Abstract

1. The activity of glutathione (GSH) transferases in rat liver cytosol was inhibited by the (-) enantiomer of a uricosuric diuretic (6,7-dichloro-5[N,N-dimethylsulphamoyl]-2,3-dihydrobenzofuran-2-carboxylic acid, DBCA) in a concentration-dependent manner. Although the DBCA (+) enantiomer inhibited the activity of liver cytosol GSH transferases, it was less effective.

2. Among four purified GSH transferase isozymes obtained from rat liver cytosol, isozyme 3–3 showed stereoselective interactions with the enantiomers of DBCA. This isozyme most actively and preferentially catalysed the transfer of GSH to DBCA (-) enantiomer.