GPT and GPT2 (EC 2.6.1.2), also known as alanine transaminases, are pyridoxal enzymes that catalyze the reversible transamination between alanine and 2-oxoglutarate to form pyruvate and glutamate. By mediating the conversion of these 4 major intermediate metabolites, these transaminases have roles in gluconeogenesis and in amino acid metabolism.