Interrelationships among Glycogen Phosphorylase Isozymes

Liver Glycogen Phosphorylase Kinase

Liver glycogen phosphorylase kinase was assayed by measuring the radioactivity of [y-32P]ATP incorporated into rabbit skeletal muscle phosphorylase b. Using this assay two forms of phosphorylase kinase, Kinase I and Kinase II, were pirified about 70and 130-fold, respectively, from rabbit liver cytosol by DEAE-Sephadex A50 column chromatography, ammonium sulfate fractionation, gel filtration on ...

Glycogen Phosphorylase in DictyosteLium discoideum

The glycogen phosphorylase of Dictyostelium discoideum has been purified over 200-fold from cells in the culmination stage of development. Analytical gel electrophoresis of the purified enzyme indicates one major protein band with a molecular weight of approximately 210,000. Gel elution verified the presence of phosphorylase activity associated with the protein band. Electrophoresis of partiall...

Comparative Studies on Glycogen Phosphorylase

The isolation and crystallization of both forms of glycogen phosphorylase from human skeletal muscle (1) have made possible a detailed study of the properties of these enzymes in comparison with those of rabbit skeletal muscle (2, 3). Phosphorylase b and a from both species have been shown to crystallize under similar conditions and to have similar pH optima, electrophoretic mobilities, sedimen...

ORDERED MECHANISM OF BINDING OF PHOSPHORYLASE KINASE AND GLYCOGEN PHOSPHORYLASE b TO GLYCOGEN

The kinetics of the interaction of rabbit skeletal muscle phosphorylase kinase with glycogen has been studied using turbidimetric method (40 mM Hepes, pH 6.8, and 8.2; 20◦C). The binding of phosphorylase kinase with glycogen occurs only in the presence of Ca and Mg . According to the kinetic data, phosphorylase b favors the binding of phosphorylase kinase with glycogen. This conclusion is suppo...

McArdle's disease-muscle glycogen phosphorylase deficiency.