The reaction mixture contained 25 mM sodium sulfate buffer (pH 7.5), 100 mM glutamine, 100 mM 2-oxoglutarate, 1.4 mM NADH for NADH-GOGAT activity or 3.9 mM methyl viologen and 190 mM DIT in a 180 mM NaHCO3 for Fd-GOGAT activity. Glutamate produced by GOGAT was determined using HPLC.