DOPA decarboxylase (DDC) belongs to the group II decarboxylase family of proteins (1). It is an important protein in the catecholamine biosynthesis pathway. DDC catalyzes the second reaction in the biosynthesis of catecholamines, trace amines and serotonin (1,2). It can form a homodimer and is expressed in the central nervous system (2). DDC can be used as markers for dopaminergic, noradrenergic and serotonergic neurons in a variety of applications including depression, schizophrenia, Parkinson's disease, neuroendocrine tumors and drug abuse (3,4). Defects in DDC gene may cause the autosomal recessive disorder AADC deficiency (4).