The activity of glycogen phosphorylase is regulated by several factors including allosteric effectors and covalent modification. For instance, AMP acts as an allosteric activator, while ATP and glucose-6-phosphate serve as inhibitors. Covalent modification, particularly phosphorylation of a specific serine residue, can convert the enzyme between its active (phosphorylase a) and less active (phosphorylase b) forms.
