H2O + L-glutamate + NADP(+) = 2-oxoglutarate + H(+) + NADPH + NH4(+) Homohexamer. Strain NRC-36014 contains 4 distinct glutamate dehydrogenases while strain NRC-1 contains only 3. Belongs to the Glu/Leu/Phe/Val dehydrogenases family.