Merck, AB1541, Anti-Tryptophan Hydroxylase Antibody

Tryptophan hydroxylase (TPH) is an enzyme involved in the synthesis of the neurotransmitter serotonin. It is responsible for addition of the -OH group (hydroxylation) to the 5 position to form the amino acid 5-hydroxytryptophan (5-HTP), which is the initial and rate-limiting step in the synthesis of the hormone serotonin. It is also the first enzyme in the synthesis of melatonin.