Turnover of skeletal muscle glycogen phosphorylase.
Glycogen phosphorylase is a major sarcoplasmic protein and is one of the key regulatory enzymes in the control of glycogen utilisation. In C57BL/6J mice, the activity of the enzyme decreases under muscle-wasting conditions, including denervation-induced atrophy and muscular dystrophy. The cofactor of this enzyme, pyridoxal phosphate, has been employed as a specific label to permit measurement of the rate of degradation of the enzyme in vivo. In both of the muscle-wasting conditions, the decay of protein-bound label occurs at a higher rate than in normal animals, suggesting accelerated degradation of the enzyme. Additionally, we have used a monoclonal antibody, specific for pyridoxal phosphate, as a sensitive probe to search for degradation intermediates of this enzyme in vivo.
D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D006019:Glycolysis; D051379:Mice; D008810:Mice, Inbred C57BL; D009132:Muscles / Q000201:enzymology*; D010084:Oxidation-Reduction; D006005:Phosphorylases / Q000378:metabolism*; D012967:Sodium Dodecyl Sulfate
D012967:Sodium Dodecyl Sulfate; D006005:Phosphorylases