Catalyzes the reversible oxidative deamination of glutamate to a-ketoglutarate and ammonia. H2O + L-glutamate + NADP(+) = 2-oxoglutarate + H(+) + NADPH + NH4(+) Homohexamer. Belongs to the Glu/Leu/Phe/Val dehydrogenases family. This sequence originates from an organism contaminating a Chlorella sorokiniana culture, probably a bacterium.