Preview

PDF 227Kb

Glycogen debranching enzyme (GDE) has 4-a-glucanotransferase and amylo-1,6-glucosidase activities in the single polypeptide chain. We analyzed the detailed action profile of GDE from Saccharomyces cerevisiae on amylose and tested whether GDE catalyzes cyclization of amylose. GDE treatment resulted in a rapid reduction of absorbance of iodine-amylose complex and the accumulation of a product that was resistant to an exoamylase (glucoamylase [GA]) but was degraded by an endo-type a-amylase to glucose and maltose. These results indicated that GDE catalyzed cyclization of amylose to produce cyclic a-1,4 glucan (cycloamylose). The formation of cycloamylose was confirmed by high-performance anion-exchange chromatography, and the size was shown to range from a degree of polymerization of 11 to a degree of polymerization around 50. The minimum size and the size distribution of cycloamylose were different from those of cycloamylose produced by other 4-a-glucanotransferases. GDE also efficiently produced cycloamylose even from the branched glucan substrate, starch, demonstrating its potential for industrial production of cycloamylose.

Item Type:	Refereed Article
Keywords:	glycogen debranching enzyme;cycloamylose production
Research Division:	Biological Sciences
Research Group:	Plant biology
Research Field:	Plant physiology
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the biological sciences
UTAS Author:	Smith, SM (Professor Steven Smith)
ID Code:	101550
Year Published:	2002
Web of Science® Times Cited:	20
Deposited By:	Plant Science
Deposited On:	2015-06-25
Last Modified:	2022-09-02
Downloads:	222 View Download Statistics