Enhanced catalytic activity of hexokinase by work-induced mitochondrial binding in fast-twitch muscle of rat.
Using a teased muscle fiber preparation, we determined the activity of mitochondrially bound hexokinase in rat fast-twitch muscle under control conditions and after low-frequency stimulation periods for up to 2 h. As compared to soluble hexokinase, mitochondrial binding led to stimulation of glucose 6-phosphate production. Low-frequency stimulation greatly enhanced glucose 6-phosphate formation which was 100% and 250% elevated after 1 and 2 h, respectively. These observations point to a mechanism which rapidly increases the catalytic activity of hexokinase through binding to the mitochondrial surface.
Parra
J
J
Faculty of Biology, University of Konstanz, Germany.
Brdiczka
D
D
Cusso
R
R
Pette
D
D
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D004558:Electric Stimulation; D019298:Glucose-6-Phosphate / Q000096:biosynthesis; D006593:Hexokinase / Q000378:metabolism*; D008297:Male; D008928:Mitochondria / Q000201:enzymology*; D009119:Muscle Contraction / Q000502:physiology*; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D010101:Oxygen Consumption; D011485:Protein Binding; D051381:Rats; D017208:Rats, Wistar
D019298:Glucose-6-Phosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D006593:Hexokinase