Purification and Characterization of Glucosyltransferase Glucanotransferase Involved in the Production of Cyclic Tetrasaccharide in Bacillus globisporus Cll and JSBA

Glucosyltransferase and glucanotransferase involved in the production of cyclic tetrasaccharide (CTS; cyclo {-,6}-ai-D-glucopyranosyl-(1-,3)-ev-D-glucopyranosyl(1--6)-a-D-glucopyranosyl-(1-3)-a-D-glucopyranosyl(1-,)) from or-1,4-glucan were purified from Bacilltts globisporus Cll. The former was a 1,6-a-glucosyltransferase (6GT) catalyzing the a-1,6-transglucosylation of one glucosyl residue to the nonreducing end of maltooligosaccharides (MOS) to produce a-isomaltosylMOS from MOS. The latter was a" isomaltosyl transferase (IMT) catalyzing a-1,3-, or-1,4-, and a,fi-1,1-intermolecular transglycosylation of isomaltosyl residues.