[Effect of 5-phosphoribosyl-1-pyrophosphate on the L-glutamate dehydrogenase activity of the bovine liver].

Bovine liver glutamate dehydrogenase (GDH) is a very complex enzyme in its molecular structure and activity regulation. The present paper deals with the effect of PRPP on GDH activity. This phosphate sugar, playing a key role in purine metabolism, behaves as an effector in the L-glutamate oxidation, showing both an activating effect (at low L-glu concentration) and an inhibiting one (as far as 40%), increasing with L-glu and coenzyme (3-acetyl-pyridine adenine dinucleotide) concentration. The inhibition is quite evident at low PRPP concentration, thus suggesting a physiologic role in cellular regulation of GDH activity.