Dopamine

By Michalina Hanzel, PhD

DOPA decarboxylase (DDC) is responsible for catalyzing the conversion of aromatic amino acids into their corresponding amines during the synthesis of several important neurotransmitters. Specifically, DDC catalyzes the decarboxylation of L-DOPA to dopamine, L5-HTP to serotonin, L-histidine to histamine, phenylalanine to phenethylamine, L-tyrosine to tyramine, and tryptophan to tryptamine.

Tyrosine hydroxylase is a member of the aromatic amino acid hydroxylase (AAAH) family.  It is expressed throughout the central nervous system (CNS) and catalyzes the conversion of tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA), which can be, through a series of downstream enzymatic reactions, processed into the neurotransmitter and signaling molecule dopamine. Dopamine can then be further altered to produce norepinephrine or epinephrine.