Kinetics, Mechanism, and Regulation of Rat Skeletal Muscle Hexokinase

Kinetics, mechanism, and regulation of rat skeletal muscle hexokinase.

Initial rate studies were employed to investigate the kinetic mechanism of action of rat skeletal muscle type II hexokinase (EC 3.7.1.1). These investigations involved the use of substrate analogs which act as competitive inhibitors and product inhibition experiments. The findings indicate that substrates n-glucose and MgATP2add randomly to hexokmase. Both products exhibit noncompetitive inhibi...

Hexokinase type II from rat skeletal muscle.

Evidence for functional hexokinase compartmentation in rat skeletal muscle mitochondria.

Further studies of mitochondrially bound hexokinase have been carried out in order to elucidate the mechanism first proposed to increase efficiency of oxidative phosphorylation by the acceptor effect (Bessman, S. P. (1954) in Fat Metabolism (Najjar, V., ed) pp. 133-137, Johns Hopkins Press, Baltimore). During isolation of mitochondria, Mg2+ caused increased quantities of hexokinase to be bound ...

Kinetics of GLUT4 Trafficking in Rat and Human Skeletal Muscle

OBJECTIVE In skeletal muscle, insulin stimulates glucose transport activity three- to fourfold, and a large part of this stimulation is associated with a net translocation of GLUT4 from an intracellular compartment to the cell surface. We examined the extent to which insulin or the AMP-activated protein kinase activator AICAR can lead to a stimulation of the exocytosis limb of the GLUT4 translo...

Kinetic studies with skeletal-muscle hexokinase.

Rat skeletal-muscle hexokinase was partially purified by ammonium sulphate fractionation and gel filtration. The mechanism of the skeletal-muscle hexokinase was studied kinetically by initial-velocity analysis and product inhibition. Glucose 6-phosphate was a non-competitive inhibitor of glucose and ATP. ADP was a non-competitive inhibitor of glucose and a competitive inhibitor of ATP. The data...