Glutamic Acid Decarboxylase (GAD) catalyzes the conversion of glutamate to gamma-aminobutyric acid (GABA), the principal inhibitory neurotransmitter in the brain. There are two isoforms of GAD, GAD65 and GAD67 (65 and 67 kDa, respectively) that are encoded by two different genes. The two isoforms have distinct intraneuronal distribution in the brain. There is 64% amino acid identity between the two isoforms, with the highest diversity located at the N terminus, which in GAD65 is required for targeting the enzyme to GABA containing secretory vesicles. GAD65 is primarily found in nerve terminals. GAD67 has been thought to be primarily located in the nerve cell body and has been identified as a major autoantigen in type 1 diabetes.
Storage: Store at -20 °C for one year. Avoid repeated freeze/thaw cycles.