Stereoselectivity and enantioselectivity of glutathione S-transferase toward stilbene oxide substrates.
Isozyme 4-4 of rat liver glutathione S-transferase catalyzes the stereoselective addition of glutathione to the oxirane carbon of R-absolute configuration of cis-stilbene oxide, 2, to give 98 +/- 2% of the (1S,2S)-1,2-diphenyl-1-(S-glutathionyl)-2-hydroxyethane product with a turnover number (kc) of 0.22 s-1. The two enantiomers of trans-stilbene oxide, 3, are somewhat poorer substrates for the enzyme. Enantioselective addition of glutathione to 3 proceeds with turnover numbers of 0.12 s-1 and 0.023 s-1 for the (R,R,)- and (S,S)-antipodes, respectively.
D000818:Animals; D005982:Glutathione Transferase / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D051381:Rats; D013237:Stereoisomerism; D013267:Stilbenes / Q000138:chemical synthesis; D013379:Substrate Specificity
D007527:Isoenzymes; D013267:Stilbenes; D005982:Glutathione Transferase; C025906:stilbene oxide