Purification and characterization of a rat liver enzyme catalyzing N-deacetylation of mercapturic acid conjugates.
An enzyme catalyzing N-deacetylation of both S-aryl- and S-aralkylmercapturic acids has been purified about 1000-fold from rat liver cytosol. The enzyme is distinct from N-acetyl-beta-alanine deacylase [EC 3.5.1.21], epsilon-acyllysine deacylase [EC 3.5.1.17], acylase I [EC 3.5.1.14], and acylase II [EC 3.5.1.15] but resembles acylase III with regard to the substrate specificity. The KM value for N-acetyl-S-(p-nitrobenzyl)-L-cysteine was 0.38 mM at optimum pH (8.5) in Tris/HCl buffer. The molecular weight of the purified deacetylase determined by gel-filtration was 145,000 +/- 10,000.
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000378:metabolism; D000581:Amidohydrolases / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D003600:Cytosol / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D046911:Macromolecular Substances; D008297:Male; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity
D046911:Macromolecular Substances; D000581:Amidohydrolases; C033751:mercapturic acid conjugate deacetylase; D000111:Acetylcysteine