Purification and properties of hydroxyindole-O-methyl transferase.

The demonstration of the hormone mclatonin (N-acetyl-Bmethoxytryptamine) in bovine pineal gland (1) prompted a study of the enzymes involved in its formation and metabolism. In preliminary studies (2, 3) we described an enzyme, hydroxyindole-O-methyl transferase, in the pineal gland of cows, that catalyzes the 0-methylation of N-acetyl-serotonin to melatonin. This paper describes the purification of the enzyme from cow pineal gland, its properties, assay, and distribution.