title: Two kinetic methods to study the regulation of mammalian hexokinases.
abstract: Two new kinetic analyses for mammalian hexokinases are presented, which permit one to study the regulation of these enzymes by product inhibition. One method uses the pyruvate kinase-coupled assay and the other the glucose-6-phosphate dehydrogenase-coupled assay. Both methods give simple linear plots, which indicate that the magnesium-ATP complex overcomes the glucose 6-phosphate inhibition competitively, but by atypical kinetics. A new regulation coefficient (Kr) was defined and it was shown that, with both assay methods, the reciprocals of the slopes of the simple linear plots are proportional to Kr.[Mg.ATP].NADP, but not NAD, was found to be a powerful inhibitor of pig heart hexokinase.
authors.affiliation: Department of Chemistry, Indiana University, Bloomington 47405.
authors.forename: W T
authors.initials: WT
authors.lastname: Jenkins
authors.forename: C C
authors.initials: CC
authors.lastname: Thompson
mesh_terms: D000818:Animals; D006593:Hexokinase / Q000378:metabolism*; D007700:Kinetics; D008433:Mathematics; D008722:Methods; D008962:Models, Theoretical; D009206:Myocardium / Q000201:enzymology; D013552:Swine
chemical_list: D006593:Hexokinase