Reaction: S-adenosyl-L-methionine + a thiopurine = S-adenosyl-L-homocysteine + a thiopurine S-methylether
Other name(s): mercaptopurine methyltransferase; thiopurine methyltransferase; 6-thiopurine transmethylase; TPMT
Systematic name: S-adenosyl-L-methionine:thiopurine S-methyltransferase
Comments: Also acts, more slowly, on thiopyrimidines and aromatic thiols. Not identical with EC 18.104.22.168 thiol S-methyltransferase.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 67339-09-7
1. Remy, C.N. Metabolism of thiopyrimidines and thiopurines. S-Methylation with S-adenosylmethionine transmethylase and catabolism in mammalian tissues. J. Biol. Chem. 238 (1963) 1078-1084.
2. Woodson, L.C., Ames, M.M., Selassie, C.D, Hansch, C. and Weinshilbaum, R.M. Thiopurine methyltransferase. Aromatic thiol substrates and inhibition by benzoic acid derivatives. Mol. Pharmacol. 24 (1983) 471-478. [PMID: 6633508]
3. Woodson, L.C. and Weinshilbaum, R.M. Human kidney thiopurine methyltransferase. Purification and biochemical properties. Biochem. Pharmacol. 32 (1983) 819-826. [PMID: 6838629]