Dextrinase

This enzyme [EC 3.2.1.10] (also referred to as oUgo-1,6-glucosidase, sucrase-isomaltase, and limit dextrinase) catalyzes the hydrolysis of l,6-o -D-glucosidic linkages in isomaltose and dextrin products generated from starch and glycogen via a-amylase. See also Sucrase... 

The majority of dextrans in nature are produced extracellularly via dextran-sucrase from sucrose by several lactic acid bacteria, principally Leuconostoc and Streptococcus species [13]. Dextran is also synthesised by dextrinase of different Gluconobacter species [56]. Referring to this enzyme, fermentation of maltodextrins leads to a- —4) branched dextrans with comparatively lower Mw. However, dextransucrase from Leuconostoc mesenteroid.es NRRL B-512F has attracted most interest because of commercial use. 

The latest International Union Biochemicals report includes an enzyme 3.2.1.41 a-dextrin endo-l,6-a-glucosidase, other names limit dextrinase, amylopectin 6-glucanohydrolase, pullulanase. 

Dohlert and Knutson (1991) and D. J. Manners (personal communication) reported that extracts of sugary maize contain a mixture of limit dextrinase and isoamylase. However, James et al. (1995) reported that su 1 codes for the isoamylase. 

The plant and bacterial enzymes capable of hydrolyzing pullulan do not have identical specificities. In particular, the plant enzymes have little or no action on glycogen and phytoglycogen under conditions in which they readily hydrolyze amylopectin and its /3-dextrin. To stress this difference (the bacterial enzymes are capable of degrading both glycogen and phytoglycogen), Manners (1997) recommended different nomenclature for bacterial enzymes, to be called pullulanase, and the plant enzymes, to be called limit dextrinases. 

Gluco-oligosaccharides (GlcOS) can be made by the action of an enzyme, dextran dextrinase produced by Gluconobacter oxydans on maltodextrins. They have been made in whole-cell bioreactors [104] and evaluated in fecal batch cultures [105] and in three-stage gut models [106]. Mountzouris et al. [104] used methylation analysis to determine the linkages of... 

Dextrinases, a-glucosidases, and disaccharidases located on the surface of the brush border of the intestinal epithelial cell complete the conversion of starch to glucose. 

An a-dextrinase cleaves a-1,6 linkages, releasing glucose residues from branched oligosaccharides. 

Dextrinases - Sugar beet refining, juice processing. 

The limit-dextrinase activity of malted barley is important in distilhng and brewing, since its activity controls the conversion of starch into fermentable sugars. ... 

Broad-bean limit-dextrinase, originally termed R-enzyme, has been used for the structural analysis of a-dextrins for example, 6 -a-maltosylmalto-triose [0-a-n-glucopyranosyl-(l—>4)-0-a-D-glucopyranosyl-(l- 6)-0-a-n-... 

Alpha-dextrin endo-1,6-alpha-glucosidase. Pullulanase. Pullulan 6-glucanohydrolase. Limit dextrinase. Debranching enzyme. 3.2.1.41 Starch-debranching enzyme, hydrolyses (l-6)-alpha-glucosidic linkages in pullulan and starch to form maltotriose. 

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