| phosphorylase | <enzyme> Enzyme that catalyses the sequential removal of glycosyl residues from glycogen to yield one glucose-1-phosphate per reaction. Its activity is controlled by phosphorylation (by phosphorylase kinase). (21 Jun 2000) |
|---|---|
| phosphorylase a | <enzyme> The phosphorylated and more active form of phosphorylase that functions as a regulatory enzyme during glycogen breakdown. The phosphate groups are hydrolytically removed by phosphorylase phosphatase to form phosphorylase b and orthophosphate. Registry number: EC 2.4.1.- (12 Dec 1998) |
| phosphorylase b | <enzyme> The relatively inactive form of phosphorylase that is reactivated to form phosphorylase a by phosphorylase kinase, which catalyses the enzymatic phosphorylation of the serine residues at the expense of ATP. Registry number: EC 2.4.1.- (12 Dec 1998) |
| phosphorylase phosphatase | <enzyme> An enzyme that deactivates glycogen phosphorylase a by releasing inorganic phosphate and phosphorylase b, the inactive form. Chemical name: (Phosphorylase a) phosphohydrolase Registry number: EC 3.1.3.17 (12 Dec 1998) |
| phosphorylase-rupturing enzyme | <enzyme> An enzyme that deactivates glycogen phosphorylase a by releasing inorganic phosphate and phosphorylase b, the inactive form. Chemical name: (Phosphorylase a) phosphohydrolase Registry number: EC 3.1.3.17 (12 Dec 1998) |
| muscle phosphorylase deficiency | Type V glycogen storage disease, affecting muscle, caused by deficiency of muscle phosphorylase. (05 Mar 2000) |
| polynucleotide phosphorylase | <enzyme> An enzyme of the transferase class that catalyses the reaction RNA(n+1) and orthophosphate to yield RNA(n) and a nucleoside diphosphate, or the reverse reaction. ADP, idp, GDP, udp, and cdp can act as donors in the latter case. Chemical name: Polyribonucleotide:orthophosphate nucleotidyltransferase Registry number: EC 2.7.7.8 (12 Dec 1998) |
| xanthosine phosphorylase | <enzyme> From E coli k-12; mw 18kda; inactivated by p-chloromercuriphenylsulfonic acid Registry number: EC 2.4.2.- Synonym: inosine-guanosine phosphorylase (26 Jun 1999) |
| purine-nucleoside phosphorylase | <enzyme> An enzyme that catalyses the reaction between a purine nucleoside and orthophosphate to form a free purine plus ribose-5-phosphate. Chemical name: Purine-nucleoside:orthophosphate ribosyltransferase Registry number: EC 2.4.2.1 (12 Dec 1998) |
| pyrimidine-nucleoside phosphorylase | <enzyme> Consider uridine phosphorylase and thymidine phosphorylase Registry number: EC 2.4.2.2 Synonym: pyrimidine nucleoside phosphorylase (26 Jun 1999) |
| nucleoside phosphorylase | <enzyme> From klebsiella sp.; acts on both purine and pyrimidine nucleosides and catalyses the production of araa from uridine arabinoside (arau) and adenine Registry number: EC 2.4.2.- (26 Jun 1999) |
| diadenosine 5,5'''-P(1),P(4)-tetraphosphate alpha,beta-phosphorylase | <enzyme> Ap4a + inorganic po4 forms ATP + ADP Registry number: EC 2.7.7.53 Synonym: ap4a phosphorylase, ATP adenylyltransferase (26 Jun 1999) |
| orotidylic acid phosphorylase | <enzyme> The enzyme catalyzing the formation of orotidine-5'-phosphoric acid (orotidylic acid) from orotic acid and 5-phosphoribosyl-1-pyrophosphate in the course of pyrimidine nucleotide biosynthesis. Chemical name: Orotidine-5'-phosphate:pyrophosphate phospho-alpha-D-ribosyltransferase Registry number: EC 2.4.2.10 (12 Dec 1998) |
| thymidine phosphorylase | <enzyme> The enzyme catalyzing the transfer of 2-deoxy-d-ribose from thymidine to orthophosphate, thereby liberating thymidine. Chemical name: Thymidine:orthophosphate deoxy-D-ribosyltransferase Registry number: EC 2.4.2.4 (12 Dec 1998) |
| urateribonucleotide phosphorylase | A ribosyltransferase that reacts urate d-ribonucleotide with orthophosphate to produce urate plus d-ribose 1-phosphate. (05 Mar 2000) |