H2O + L-glutamate + NADP(+) = 2-oxoglutarate + H(+) + NADPH + NH4(+) Homo- and heterohexamer of alpha and beta subunits. Both subunits are encoded by the same gene. By ammonium. The N-termini of the alpha and the beta chains are blocked. Belongs to the Glu/Leu/Phe/Val dehydrogenases family.