'Phosphorylase' is a family of
allosteric enzymes that
catalyze the production of
glucose-1-phosphate from a polyglucose such as
glycogen,
starch or
maltodextrin.
Function
More generally, phosphorylases are enzymes that catalyze the addition of a phosphate group from an inorganic phosphate (phosphate+hydrogen) to an acceptor. Do not confuse this enzyme with a
phosphatase or a
kinase. A phosphatase removes a phosphate group from a donor, while a kinase transfers a phosphate group from a donor (usually ATP) to an acceptor.
Types
The phosphorylases are named by prepending the name of the substrate, e.g.
glycogen phosphorylase,
starch phosphorylase,
maltodextrin phosphorylase.
All 'known' phosphorylases share catalytic and structural properties
[1].
Activation
'Phosphorylase a' is the active form of glycogen phosphorylase that is derived from the phosphorylation of the inactive form, 'phosphorylase b'.
Pathology
Some disorders are related to phosphorylases:
★
Glycogen storage disease type V - muscle glycogen
★
Glycogen storage disease type VI - liver glycogen
External links
★