Specific for (1¡ú6)-¦Á-D-glucans (dextrans) and, unlike cyclomaltodextrin glucanotransferase (EC 2.4.1.19), without activity towards (1¡ú4)-¦Á-D-glucans, such as amylose. It also has no activity on oligosaccharides, such as amylopectin and pullulan, containing (1¡ú6)-¦Á-D-glucosidic linkages at branch points. The enzyme from Bacillus circulans T-3040 has been shown to form cycloisomalto-oligosaccharides of three sizes (7, 8 and 9 glucose units). It will also catalyse the disproportionation of two isomalto-oligosaccharides molecules to yield a series of isomalto-oligosachharides and the addition of D-glucose to cycloisomalto-oligosaccharides with ring opening to form isomalto-oligosaccharides.
Cofactor
History
Reactions
Cyclizes part of a (1->6)-alpha-D-glucan chain by formation of a (1->6)- alpha-D-glucosidic bond.
