title: Enzymatic synthesis of novel branched sugar alcohols mediated by the transglycosylation reaction of pullulan-hydrolyzing amylase II (TVA II) cloned from Thermoactinomyces vulgaris R-47.
abstract: Transglycosylation reactions are useful for preserving a specific sugar structure during the synthesis of branched oligosaccharides. We have previously reported a panosyl unit transglycosylation reaction by pullulan-hydrolyzing amylase II (TVA II) cloned from Thermoactinomyces vulgaris R-47 (Tonozuka et al., Carbohydr. Res., 1994, 261, 157-162). The acceptor specificity of the TVA II transglycosylation reaction was investigated using pullulan as the donor and sugar alcohols as the acceptor. TVA II transferred the α-panosyl unit to the C-1 hydroxyl group of meso-erythritol, C-1 and C-2 of xylitol, and C-1 and C-6 of d-sorbitol. TVA II differentiated between the sugar alcohols' hydroxyl groups to produce five novel non-reducing branched oligosaccharides, 1-O-α-panosylerythritol, 1-O-α-panosylxylitol, 2-O-α-panosylxylitol, 1-O-α-panosylsorbitol, and 6-O-α-panosylsorbitol. The Trp(356)→Ala mutant showed similar transglycosylation reactions; however, panose production by the mutant was 4.0-4.5-fold higher than that of the wild type. This suggests that Trp(356) is important for recognizing both water and the acceptor molecules in the transglycosylation and the hydrolysis reaction.
authors: Department of Biotechnology, Akita Prefectural University, Shimoshinjo-Nakano, Akita, Japan. yshimura@akita-pu.ac.jp
authors: Yoichiro
authors: Y
authors: Shimura
authors: Keimei
authors: K
authors: Oh
authors: Misaki
authors: M
authors: Kon
authors: Eri
authors: E
authors: Yamamoto
authors: Yoshinori
authors: Y
authors: Mizuno
authors: Takashi
authors: T
authors: Adachi
authors: Tomomi
authors: T
authors: Abe
authors: Shigeru
authors: S
authors: Tamogami
authors: Jun
authors: J
authors: Fukushima
authors: Tamio
authors: T
authors: Inamoto
authors: Takashi
authors: T
authors: Tonozuka
mesh_terms: D000681:Amylases / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D005936:Glucans / Q000378:metabolism*; D015394:Molecular Structure; D013402:Sugar Alcohols / Q000378:metabolism*; D056509:Thermoactinomyces / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D005936:Glucans; D013402:Sugar Alcohols; C009109:pullulan; D000681:Amylases