グリコシダーゼ類の基質特異性における柔軟性 : 非天然型オリゴ糖,配糖体合成への利用の可能性  [in Japanese] Flexibility of Glycosidases in Substrate Specificity : Their Possible Application to the Synthesis of Unusual Oligosaccharides and Glycosides  [in Japanese]

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Author(s)

Abstract

Specificities of glycosidases were studied from the viewpoint of the synthesis of oligosaccharides and glycosides that are not naturally occurring. Trehalase from Lobosphaera sp. catalyzed conden-sation not only of glucose (Glc) but also of 2-deoxy glucose (dGlc), yielding trehalose and dideoxy-trehalose, respectively. Deoxy-trehalose was also synthesized in a mixture of Glc and dGlc. Activi-ties for trehalose derivatives decreased considerably because of their deoxy site. Glucoamylases from Aspergillus niger and Rhizopus niveus, and α-glucosidase from A. niger afforded deoxy-oli-gosaccharides by the condensation of dGlc, while α-glucosidases from Torula and Saccharomyces gave them in low yields. Deoxy-glucobioses with α-1, 3-, 1, 4- and 1, 6-linkages were identified as the products of glucoamylase and α-glucosidase. The hydrolysis rates of these glucobioses and the transfer action of α-glucosidase seemed to affect the product composition, especially in the early stage of the reactions, and afterwards, the 1, 6-linked saccharide accumulated predominately. Strains of Clavibacter michiganense and Flavobacterium johnsonae produced novel β-glucosidases that hydrolyzed the β-glucosyl ester linkage of steviol glycosides. Transglucosylation occurred when this linkage was degraded, ρ-Hydroxybenzoyl glucose was chemically synthesized as a substrate containing the β-glucosyl ester linkage. Several β-glucosidases, such as that from Caldocellum saccharolyticum, hydrolyzed the substrate. ρ-Hydroxybenzoyl galactose with the β-galactosyl ester linkage was also synthesized, and was examined as a substrate for β-galactosidases. The activities showed great diversity depending on the enzyme origin. The enzyme from Penicillium multicolor showed the highest activity among those tested. β-Galactosidases catalyzed galactosylation not only of a hydroxyl group but also of a thiol group in the condensation of galactose and 2-mercap-toethanol. The enzymes from <I>A</I>. oryzae and <I>P</I>. multicolor were effective for the synthesis of thio-galactoside. The usual galactoside was synthesized more rapidly than the thin-galactoside, although the latter accumulated predominately as the reaction proceeded.

Journal

  • Journal of Applied Glycoscience

    Journal of Applied Glycoscience 47(2), 261-267, 2000-06-30

    The Japanese Society of Applied Glycoscience

References:  11

Codes

  • NII Article ID (NAID)
    10008252006
  • NII NACSIS-CAT ID (NCID)
    AN10453916
  • Text Lang
    JPN
  • Article Type
    REV
  • ISSN
    13403494
  • NDL Article ID
    5436151
  • NDL Source Classification
    ZP24(科学技術--化学・化学工業--糖・澱粉)
  • NDL Call No.
    Z17-15
  • Data Source
    CJP  NDL  J-STAGE 
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