L-Glutamic Dehydrogenase from bovine liver

Substrate Specificity

L-glutamate + NAD⁺ + H₂O = 2-oxoglutarate + NH₄⁺ + NADH + H⁺ || L-glutamate + NADP⁺ + H₂O = 2-oxoglutarate + NH₄⁺ + NADPH + H⁺

L-glutamic dehydrogenase was used to catalyze the conversion of isocitrate into α-ketoglutarate and carbon dioxide.

Mammalian forms of this enzyme, including this bovine form, can use either NADP(H) or NAD(H) as coenzymes. L-glutamic dehydrogenase plays a unique role in mammalian metabolism. The reverse reaction catalyzed by this enzyme is the only pathway by which ammonia can become bound to the α-carbon atom of an α-carboxylic acid and thus, is the only source of de novo amino acid synthesis in mammalian species.

The bovine enzyme is characterized by three sets of properties:

• It has a reversible concentration-dependent association, producing higher molecular weight forms.
• Forms tight enzyme-reduced coenzyme-substrate ternary complexes whose rates of dissociation modulate the steady-state reaction rates.
• Exhibits a wide variety of effects from the binding of any of a number of nucleotide modifiers.

L-glutamic dehydrogenase catalyzes the conversion of glutamate to α-ketoglutarate.

50% glycerol solution

Protein determined by biuret.

One unit will reduce 1.0 μmole of α-ketoglutarate to L-glutamate per min at pH 7.3 at 25 °C, in the presence of ammonium ions.