In the process of transamination, the amino groups of most amino acid are transferred to α-ketoglutarate to produce glutamate. The glutamate serves as a collection centre for amino groups in the biological system. Glutamate rapidly undergoes oxidative deamination catalysed by glutamate dehydrogenase (GDH) to liberate ammonia. This enzyme is unique, in that it can utilise either NAD⁺ or NAD⁺ as coenzyme. Glutamate dehydrogenase catalysed reaction is important as it reversibly links up glutamate metabolism with TCA cycle through α-ketoglutarate. GDH is involved in both catabolic and anabolic reactions.