title: Acetylation of aromatic cysteine conjugates by recombinant human N-acetyltransferase 8.
abstract: 1. The mercapturic acid (MA) pathway is a metabolic route for the processing of glutathione conjugates to MA (N-acetylcysteine conjugates). An N-acetyltransferase enzyme, NAT8, catalyzes the transfer of an acetyl group from acetyl-CoA to the cysteine amino group, producing a MA, which is excreted in the urine. We expressed human NAT8 in HEK293T cells and developed an HPLC-MS method for the quantitation of the S-aryl-substituted cysteine conjugates and their MA. 2. We measured the activity of the enzyme for acetylation of benzyl-, 4-nitrobenzyl-, and 1-menaphthylcysteine substrates. 3. NAT8 catalyzed the acetylation of all three cysteine conjugates with similar Michaelis-Menten kinetics.
authors.affiliation: a Department of Molecular and Cellular Biology , University of Guelph , Guelph , Ontario , Canada.
authors.forename: Reema
authors.initials: R
authors.lastname: Deol
authors.affiliation: a Department of Molecular and Cellular Biology , University of Guelph , Guelph , Ontario , Canada.
authors.forename: P David
authors.initials: PD
authors.lastname: Josephy
mesh_terms: D000107:Acetylation; D000123:Acetyltransferases / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans
chemical_list: D000123:Acetyltransferases; C116373:NAT8 protein, human; D005978:Glutathione; D003545:Cysteine
keywords: 1-menaphthylcysteine; 4-nitrobenzylcysteine; Benzylcysteine; N-acetyltransferase; NAT8; mercapturic acid pathway