Reaction: UDP-α-D-glucose + [(1→4)-α-D-glucosyl]n = UDP + [(1→4)-α-D-glucosyl]n+1
For diagram of reaction click here
Other name(s): UDP-glucose—glycogen glucosyltransferase; glycogen (starch) synthetase; UDP-glucose-glycogen glucosyltransferase; UDP-glycogen synthase; UDPG-glycogen synthetase; UDPG-glycogen transglucosylase; uridine diphosphoglucose-glycogen glucosyltransferase
Systematic name: UDP-α-D-glucose:glycogen 4-α-D-glucosyltransferase (configuration-retaining)
Comments: The accepted name varies according to the source of the enzyme and the nature of its synthetic product (cf. EC 2.4.1.1, phosphorylase). Glycogen synthase from animal tissues is a complex of a catalytic subunit and the protein glycogenin. The enzyme requires glucosylated glycogenin as a primer; this is the reaction product of EC 2.4.1.186 (glycogenin glucosyltransferase). A similar enzyme utilizes ADP-glucose (EC 2.4.1.21, starch synthase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9014-56-6
References:
1. Algranati, I.D. and Cabib, E. The synthesis of glycogen in yeast. Biochim. Biophys. Acta 43 (1960) 141-142. [PMID: 13682402]
2. Basu, D.K. and Bachhawat, B.K. Purification of uridine diphosphoglucose-glycogen transglucosylase from sheep brain. Biochim. Biophys. Acta 50 (1961) 123-128. [PMID: 13687710]
3. Leloir, L.F. and Cardini, C.E. UDPG-glycogen transglucosylase. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Eds.), The Enzymes, 2nd edn., vol. 6, Academic Press, New York, 1962, pp. 317-326.
4. Leloir, L.F. and Goldemberg, S.H. Synthesis of glycogen from uridine diphosphate glucose in liver. J. Biol. Chem. 235 (1960) 919-923. [PMID: 14415527]
5. Pitcher, J., Smythe, C. and Cohen, P. Glycogenin is the priming glucosyltransferase required for the initiation of glycogen biogenesis in rabbit skeletal muscle. Eur. J. Biochem. 176 (1988) 391-395. [PMID: 2970965]