One unit of activity was defined as the amount of enzyme catalyzing 1 μmol
of NADH or NADPH per min. GLR was analyzed by HPLC for Dglutamate, and one unit of activity was defined as the amount of
enzyme catalyzing the formation of 1 μmol of D-glutamate per
minute. Protein concentration was determined by Bradford method
with bovine serum albumin as the standard