Tags: Protein.
Histamine N-methyltransferase (HMT HNMT) is an enzyme that in humans is encoded by the HNMT gene.Histamine N-methyltransferase is one of two enzymes involved in the metabolism of histamine the other being diamine oxidase. Histamine N-methyltransferase catalyzes the methylation of histamine in the presence of S-adenosylmethionine (SAM) forming N-methylhistamine. HMT is present in most body tissues but is not present in serum.