PYGL Proteins and Enzymes

Phosphorylase is an important allosteric enzyme in carbohydrate metabolism. Enzymes from different sources differ in their regulatory mechanisms and in their natural substrates. However, all known phosphorylases share catalytic and structural properties. Activity of phosphorylase is controlled both by allosteric means (through the noncovalent binding of metabolites) and by covalent modification. Thus AMP allosterically activates, whereas ATP, ADP, and glucose 6 phosphate allosterically inhibit, phosphorylase B.