N-hydroxyarylamine O-acetyltransferase in hamster liver: identity with arylhydroxamic acid N,O-acetyltransferase and arylamine N-acetyltransferase.
N-Hydroxyarylamine O-acetyltransferase, arylhydroxamic acid N,O-acetyltransferase, and arylamine N-acetyltransferase in hamster liver cytosol were co-purified almost to electrophoretical homogeneity by ion exchange chromatography on DEAE-cellulose, gel filtration on Cellulofine GCL-2000-sf and high-performance KB-hydroxyapatite chromatography. The molecular weight of the acetyltransferase was estimated to be 33,000 by gel filtration and SDS-polyacrylamide gel electrophoresis. The three acetyltransferase activities were inhibited by iodoacetamide, pentachlorophenol, and 1-nitro-2-naphthol. Furthermore, 2-aminofluorene, a substrate for arylamine N-acetyltransferase, inhibited the reactions of N-hydroxyarylamine O-acetyl transfer and arylhydroxamic acid N,O-acetyl transfer. These results suggest that the same enzyme catalyzes the three types of acetyl transfer reactions. The acetyltransferase could activate N-hydroxyarylamines, such as 2-hydroxyamino-6-methyldipyrido[1,2-alpha:3',2'-d]imidazole, 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole, and N-hydroxy-2-aminofluorene, to the corresponding N-acetoxyarylamines, which are capable of binding to nucleic acid. Polyguanylic acid was most efficiently modified by the N-acetoxyarylamines formed by the acetyltransferase.
D000123:Acetyltransferases / Q000302:isolation & purification*; D000217:Acyltransferases / Q000302:isolation & purification; D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000145:classification / Q000302:isolation & purification*; D002845:Chromatography / Q000379:methods; D006224:Cricetinae; D003600:Cytosol / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D008099:Liver / Q000201:enzymology*; D008297:Male; D008647:Mesocricetus; D008970:Molecular Weight; D013379:Substrate Specificity
D000217:Acyltransferases; D000123:Acetyltransferases; C019736:N-hydroxyarylamine O-acetyltransferase; D001191:Arylamine N-Acetyltransferase