Related Experiment Video
Updated: Aug 19, 2026

Determination of Protein-ligand Interactions Using Differential Scanning Fluorimetry
Published on: September 13, 2014
[Negative cooperativity of 6-phosphogluconate dehydrogenase in rat liver]
Abstract:
The effect of various NADPH concentrations on the activity of rat liver 6-phosphogluconate dehydrogenase (EC 1.1.1.44) has been studied. The influence of NADPH concentrations on the enzyme cooperativity was observed. NADPH used at concentration up to 200 microM appeared to be a competitive inhibitor with respect to NADP+ without any cooperative effect towards the coenzyme (NADP+) binding. At high concentrations of NADPH (above 300 microM) the negative cooperativity displayed by the enzyme was confirmed by a significant decrease of the Hill coefficient for NADP(+)-from 1.1 +/- 0.2 down to 0.6 +/- 0.1 (p < 0.05).
Related Concept Videos
Allosteric Regulation
Cooperative Allosteric Transitions
Cell Specific Gene Expression
Glycolysis: Preparatory Phase
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Other Glycolytic Pathways

