4-alpha-glucanotransferase

In enzymology, a 4-alpha-glucanotransferase (EC 2.4.1.25) is an enzyme that catalyzes a chemical reaction that transfers a segment of a 1,4-alpha-D-glucan to a new position in an acceptor carbohydrate, which may be glucose or a 1,4-alpha-D-glucan.

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is 1,4-alpha-D-glucan:1,4-alpha-D-glucan 4-alpha-D-glycosyltransferase. Other names in common use include disproportionating enzyme, dextrin glycosyltransferase, D-enzyme, debranching enzyme maltodextrin glycosyltransferase, amylomaltase, and dextrin transglycosylase. This enzyme participates in starch and sucrose metabolism.

Structural studies

As of late 2007, 14 structures have been solved for this class of enzymes, with PDB accession codes 1CWY, 1ESW, 1FP8, 1FP9, 1K1W, 1K1X, 1K1Y, 1LWH, 1LWJ, 1TZ7, 1X1N, 2OWC, 2OWW, and 2OWX.

References

• Hehre EJ (1951). "Enzymic synthesis of polysaccharides: a biological type of polymerization". Adv. Enzymol. Relat. Subj. Biochem.. Advances in Enzymology - and Related Areas of Molecular Biology 11: 297–337. doi:10.1002/9780470122563.ch6. ISBN 9780470122563. 
• Lukomskaya, I. S. (1959). "[Synthesis of oligosaccharides with alpha-1,6-bonds by enzyme preparations from liver and muscle]" (in Russian). Doklady Akademii Nauk SSSR 129: 1172–1175. 
• Pazur JH, Okada S (1968). "The isolation and mode of action of a bacterial glucanosyltransferase". J. Biol. Chem. 243 (18): 4732–8. PMID 4972097. 
• Walker GJ and Whelan WJ (1959). "Synthesis of amylose by potato D-enzyme". Nature 183 (4653): 46. doi:10.1038/183046a0. PMID 13622683. 
• Whelan WH (1971). "Enzymic explorations of the structures of starch and glycogen". Biochem. J. 122 (5): 609–622. PMC 1176828. PMID 5001952. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1176828.