|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 220.127.116.11
In Pathway: glycogen degradation I
Note that this reaction equation differs from the official Enzyme Commission reaction equation for this EC number, which can be found here .
The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.
Mass balance status: Balanced.
Enzyme Commission Primary Name: glycogen phosphorylase
Enzyme Commission Synonyms: muscle phosphorylase a and b, amylophosphorylase, polyphosphorylase, amylopectin phosphorylase, glucan phosphorylase, α-glucan phosphorylase, 1,4-α-glucan phosphorylase, glucosan phosphorylase, granulose phosphorylase, maltodextrin phosphorylase, muscle phosphorylase, myophosphorylase, potato phosphorylase, starch phosphorylase, 1,4-α-D-glucan:phosphate α-D-glucosyltransferase, phosphorylase (ambiguous)
Enzyme Commission Summary:
This entry covers several enzymes from different sources that act in vivo on different forms of (1→4)-α-D-glucans. Some of these enzymes catalyse the first step in the degradation of large branched glycan polymers - the phosphorolytic cleavage of α-1,4-glucosidic bonds from the non-reducing ends of linear poly(1→4)-α-D-glucosyl chains within the polymers. The enzyme stops when it reaches the fourth residue away from an α-1,6 branching point, leaving a highly branched core known as a limit dextrin. The accepted name of the enzyme should be modified for each specific instance by substituting "glycogen" with the name of the natural substrate, e.g. maltodextrin phosphorylase, starch phosphorylase, etc.
Fischer70: Fischer EH, Pocker A, Saari JC (1970). "The structure, function and control of glycogen phosphorylase." In: Campbell, P.N. and Greville, G.D. (Eds), Essays in Biochemistry, vol. 6, Academic Press, London and New York, pp. 23-68.
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