Purification and characterization of S-phenacylglutathione reductase from rat liver.
An enzyme catalyzing the reduction of S-(2,4-dichlorophenacyl)glutathione to 2',4'-dichloroacetophenone was purified to apparent homogeneity by ion exchange, gel filtration, and hydroxylapatite chromatography from rat hepatic cytosol. The molecular weight was 30,000-37,000. The enzyme is distinct from the glutathione S-transferases, mercaptopyruvate sulfurtransferase, and glyoxalase I. Substrate specificity studies showed that S-phenacylglutathiones are the preferred first substrates and that several thiols (glutathione, mercaptoethanol, L-cysteine, or cysteamine) serve as reducing substrates. The enzyme serves to convert toxic alpha-haloketones, which react rapidly and nonenzymatically with glutathione, to nontoxic alkyl ketones.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005980:Glutathione Reductase / Q000032:analysis / Q000302:isolation & purification*; D008099:Liver / Q000201:enzymology*; D008297:Male; D008970:Molecular Weight; D010088:Oxidoreductases / Q000302:isolation & purification*; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity
D000596:Amino Acids; D010088:Oxidoreductases; D005980:Glutathione Reductase; C046614:S-phenacylglutathione reductase