Arylamine N-methyltransferase. Methylation of the indole ring.
Arylamine N-methyltransferase catalyzes the novel methylation of the ring nitrogen of tryptamine and pyrrole as well as a number of other arylamines including aniline and its derivatives. S-Adenosyl-L-methionine serves as donor. Tyramine, indole, benzylamine, and desmethylimipramine were inactive as methyl group acceptors. The enzyme was purified from rabbit liver to electrophoretic homogeneity and was characterized as a protein monomer of 27,000 daltons with a pI of 4.8. The kinetic mechanism appears to be rapid equilibrium random Bi-Bi.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D007211:Indoles; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008745:Methylation; D008780:Methyltransferases / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D011817:Rabbits; D013379:Substrate Specificity
D000596:Amino Acids; D007211:Indoles; D008780:Methyltransferases; C033552:tryptamine N-methyltransferase