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EC number2.4.1.25
CAS number9032-09-1
IntEnzIntEnz view
ExPASyNiceZyme view
MetaCycmetabolic pathway
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO

In enzymology, a 4-alpha-glucanotransferase (EC 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 in plants.[1][2] Studies of the enzyme from potato led to the discovery of cycloamylose.[3]

Structural studies[edit]

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.


  1. ^ Critchley, Joanna H.; Zeeman, Samuel C.; Takaha, Takeshi; Smith, Alison M.; Smith, Steven M. (2001-04-01). "A critical role for disproportionating enzyme in starch breakdown is revealed by a knock-out mutation in Arabidopsis". The Plant Journal. 26 (1): 89–100. doi:10.1046/j.1365-313x.2001.01012.x. ISSN 1365-313X.
  2. ^ Chia, Tansy; Thorneycroft, David; Chapple, Andrew; Messerli, Gaëlle; Chen, Jychian; Zeeman, Samuel C.; Smith, Steven M.; Smith, Alison M. (2004-03-01). "A cytosolic glucosyltransferase is required for conversion of starch to sucrose in Arabidopsis leaves at night". The Plant Journal. 37 (6): 853–863. doi:10.1111/j.1365-313X.2003.02012.x. ISSN 1365-313X.
  3. ^ Takaha, Takeshi; Yanase, Michiyo; Takata, Hiroki; Okada, Shigetaka; Smith, Steven M. (1996-02-09). "Potato D-enzyme Catalyzes the Cyclization of Amylose to Produce Cycloamylose, a Novel Cyclic Glucan". Journal of Biological Chemistry. 271 (6): 2902–2908. doi:10.1074/jbc.271.6.2902. ISSN 0021-9258. PMC 1147477.
  • 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&ndash, 337. doi:10.1002/9780470122563.ch6. ISBN 978-0-470-12256-3.
  • Lukomskaya, I. S. (1959). "Синтез oligosaccharides с alpha-1,6-bonds приготовлениями фермента от печени и мускула" [Synthesis of oligosaccharides with alpha-1,6-bonds by enzyme preparations from liver and muscle]. Doklady Akademii Nauk SSSR (in Russian). 129: 1172&ndash, 1175.
  • Pazur JH, Okada S (1968). "The isolation and mode of action of a bacterial glucanosyltransferase". J. Biol. Chem. 243 (18): 4732&ndash, 8. PMID 4972097.
  • Walker GJ, 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&ndash, 622. PMC 1176828. PMID 5001952.