Reports

Physiological Concentrations of Lactate Dehydrogenases and Substrate Inhibition

Science  05 Jun 1970:
Vol. 168, Issue 3936, pp. 1236-1238
DOI: 10.1126/science.168.3936.1236

Abstract

Lactate dehydrogenases at physiological concentrations are inhibited by high concentrations of pyruvate when the enzyme and the pyruvate are incubated in the presence of oxidized nicotinamide-adenine dinucleotide before assay. The inhibition is much more pronounced with the H-type than with the M-type lactate dehydrogenase. These results suggest that substrate inhibition may be operative in vivo.