Glutamate synthase (NADH)

In enzymology, a glutamate synthase (NADH) (EC 1.4.1.14) is an enzyme that catalyzes the chemical reaction

2 L-glutamate + NAD⁺ ${\displaystyle \rightleftharpoons }$ L-glutamine + 2-oxoglutarate + NADH + H⁺

Glutamate synthase facilitates the ammonium assimilation pathway, which follows the enzymes, nitrite reductase and glutamine synthase.[1] An ammonium produced by the nitrite reductase reaction will be incorporated into carbon skeleton backbone by glutamine synthase.[2] Glutamine will be produced because of the introduction of ammonium in the carbon backbone, which can be converted into glutamate by glutamate synthase of another pathway.[2]

These processes are common in plant roots due to the fact that if the nitrogen deficient conditions exist (with access to ammonium and nitrate ions), there will be a first priority of ammonium uptake.[1] Thus, the two substrates of this enzyme are L-glutamate and NAD⁺, whereas its 4 products are L-glutamine, 2-oxoglutarate, NADH, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH₂ group of donors with NAD⁺ or NADP⁺ as acceptor. This enzyme participates in glutamate metabolism and nitrogen assimilation. It employs one cofactor, FMN.