Hydrolysis of branched cyclodextrins by a cyclodextrin-hydrolyzing enzyme from Bacillus sphaericus E-244

The action of a cyclodextrin-hydrolyzing enzyme from Bacillus sphaericus E-244 on branched alpha- and beta-cyclodextrins was investigated. Glucosyl-alpha-cyclodextrin (6-O-alpha-D-glucosylcyclomaltohexaose) and maltosyl-alpha-cyclodextrin (6-O-alpha-D-maltosylcyclomaltohexaose) were hydrolyzed to 6(3)-O-alpha-D-glucosylmaltohexaose and 6(3)-O-alpha-D-maltosylmaltohexaose, respectively. Glucosyl-beta-cyclodextrin (6-O-alpha-D-glucosylcyclomaltoheptose) and maltosyl-beta-cyclodextrin (6-O-alpha-D-maltosyclomaltohepatose) were also mainly transformed to 6(4)-O-alpha-D-glucosylmaltoheptaose and 6(4)-O-alpha-D-maltosylmaltoheptaose, respectively. These results suggest that the cyclodextrin-hydrolyzing enzyme cleaves branched alpha- and beta-cyclodextrins at an alpha-1,4 linkage which is located furthest from the branching point on the cyclodextrin ring.