title: Acceptor specificity of 4-alpha-glucanotransferase from Pyrococcus kodakaraensis KOD1, and synthesis of cycloamylose.
abstract: 4-Alpha-glucanotransferase from a hyperthermophilic archaeon Pyrococcus kodakaraensis KOD1 showed a broad acceptor specificity to various saccharides in an intermolecular transglycosylation reaction. In particular, the enzyme produced large amounts of transfer products of various acceptors such as D-glucose, methyl-alpha-D-glucoside, phenyl-alpha-D-glucoside, and D-xylose. It is suggested that the requirement for an effective acceptor in the intermolecular transglycosylation reaction catalyzed by this enzyme is the pyranose structure with the same configurations of the free C2-, C3-, and C4-hydroxyl groups as d-glucopyranose, like cyclomaltodextrin glucanotransferase (CGTase). However, the enzyme showed some acceptor specificities unlike those of CGTase. Analysis of the action of 4-alpha-glucanotransferase indicated that the enzyme catalyzes an intramolecular trans-glycosylation (cyclization) reaction of amylose to produce cyclic alpha-1,4-glucan (cycloamylose). The yield of cycloamylose reached 67%, and the degree of polymerization was found to range from 16 to above 55.
authors.affiliation: Research and Development Center, Nagase Co. Ltd., 2-2-3 Murotani, Nishi-ku, Kobe 651-2241, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tachibana
authors.forename: T
authors.initials: T
authors.lastname: Takaha
authors.forename: S
authors.initials: S
authors.lastname: Fujiwara
authors.forename: M
authors.initials: M
authors.lastname: Takagi
authors.forename: T
authors.initials: T
authors.lastname: Imanaka