New dioscin-glycosidase hydrolyzing multi-glycosides of dioscin from Absidia strain

J Microbiol Biotechnol. 2010 Jun;20(6):1011-7. doi: 10.4014/jmb.0910.10039.

Abstract

A novel dioscin-glycosidase that specifically hydrolyzes multi-glycosides such as 3-O-alpha-L-(1 --> 4)-rhamnoside, 3-O-alpha-L-(1 --> 2)-rhamnoside, 3-O-alpha-L-(1 --> 4)-arabinoside and beta-D-glucoside on diosgenin was isolated from Absidia sp.d38 strain; and it was purified and characterized. The molecular weight of the new dioscin-glycosidase is about 55 kDa in SDS-PAGE. The the dioscin-glycosidase gradually hydrolyzes either 3-O-alpha-L-(1 --> 4)-Rha or 3-O-alpha-L-(1 --> 2)-Rha of dioscin to 3-O-alpha-L-Rha-beta-D-Glc-diosgenin; further rapidly hydrolyzes the other alpha-L-Rha of 3-O-alpha-L-Rha-beta-D-Glc-diosgenin to main intermediate products 3-O-beta-D-glc-diosgenin; and subsequently hydrolyzes intermediate products to final product of aglycone; the new enzyme also gradually hydrolyzes 3-O-alpha-L-(1 --> 4)-arabinoside, 3-O-alpha-L-(1 --> 2)-rhamnoside and beta-D-glucoside of [3-O-alpha-L-(1 --> 4)-Ara, 3-O-alpha-L-(1 --> 2)-Rha]-beta-D-Glc-diosgenin into final product diosgenin, exhibiting significant differences from previously reported glycosidases. The optimal temperature of the new dioscin-glycosidase is 40 degrees C and the optimal pH is 5.0. The activity of the new dioscin-glycosidase was not affected by the Na+, K+ and Mg2+ ions; it was significantly inhibited by the Cu2+ and Hg2+ ions; and it was slightly affected by the Ca2+ ions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absidia / chemistry
  • Absidia / enzymology*
  • Absidia / metabolism
  • Diosgenin / analogs & derivatives*
  • Diosgenin / chemistry
  • Diosgenin / metabolism
  • Enzyme Stability
  • Fungal Proteins / chemistry
  • Fungal Proteins / isolation & purification
  • Fungal Proteins / metabolism*
  • Glycoside Hydrolases / chemistry
  • Glycoside Hydrolases / isolation & purification
  • Glycoside Hydrolases / metabolism*
  • Glycosides / chemistry
  • Glycosides / metabolism*
  • Hydrolysis
  • Kinetics

Substances

  • Fungal Proteins
  • Glycosides
  • dioscin
  • Glycoside Hydrolases
  • Diosgenin