NMR investigation of the catalytic mechanism of arylamine N-acetyltransferase from Salmonella typhimurium

• Published in: Biochimica et biophysica acta Vol. 1620; no. 1; pp. 8 - 14
• Main Authors: Delgoda, Rupika, Lian, Lu-Yun, Sandy, James, Sim, Edith
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 17.03.2003
• Subjects: Arylamine N-acetyltransferase; Arylamine N-Acetyltransferase - chemistry; Arylamine N-Acetyltransferase - metabolism; Carcinogenesis; Coenzyme A - metabolism; Drug metabolism; Isoniazid; Isoniazid - metabolism; Magnetic Resonance Spectroscopy - methods; Nuclear magnetic resonance; nuclear magnetic resonance spectroscopy; Protein Conformation; Recombinant Proteins - chemistry; Salmonella typhimurium - enzymology; Substrate Specificity; NAT; INH; Drug metabolism; Arylamine N-acetyltransferase; Nuclear magnetic resonance; Pabaglu; Isoniazid; Carcinogenesis
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/S0304-4165(02)00500-7

Arylamine N-acetyltransferases (NAT) are a family of enzymes found in both eucaryotes and procaryotes, which catalyse the N-acetylation of a range of arylamine and hydrazine drugs and carcinogenic arylamines, using acetyl Coenzyme A as a cofactor. Here we describe a nuclear magnetic resonance (NMR) investigation of the interaction of substrates with Salmonella typhimurium NAT. For solution NMR investigations, pure recombinant NAT from S. typhimurium was used at up to 0.1 mM. We demonstrate that a hydrazine substrate, isoniazid (INH), binds to the protein in the absence of the cofactor, acetyl CoA, and thereby suggest that even though the catalysis may follow a ping-pong pathway, ligand–enzyme interactions can occur in the absence of acetyl CoA.