EC=2.4.1.1
Liver form
847AA
Function
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.
Catalytic activity
(1,4-alpha-D-glucosyl)(n) + phosphate = (1,4-alpha-D-glucosyl)(n-1) + alpha-D-glucose 1-phosphate.
Cofactor
Pyridoxal phosphate.
Enzyme regulation
活性はアロステリックに、および共有結合性の修飾により調節沙sれる。AMPは活性化因子でATPとADP、グルコース6-リン酸は阻害因子である。
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.
Subunit structure
Homodimer. Dimers associate into a tetramer to form the enzymatically active phosphorylase A. Interacts with PPP1R3B By similarity.
Post-translational modification
Phosphorylation of Ser-15 converts phosphorylase B (unphosphorylated) to phosphorylase A.
Involvement in disease
セリン15がリン酸化を受けると活性型のＡ型、脱リン酸化がＢ型である。
Glycogen storage disease 6 (GSD6) [MIM:232700]: A metabolic disorder characterized by mild to moderate hypoglycemia, mild ketosis, growth retardation, and prominent hepatomegaly. Heart and skeletal muscle are not affected.
Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.4
Sequence similarities
