Purification and Characterization of Ginsenoside Rb3 Xylosidase

A ginsenoside Rb3 xylosidase from ploughshares mildew strains Absidia sp. Grb3-x8r was purified using DEAE-Cellulose DE52 ion exchange column chromatography method. The purified xylosidase showed a single protein band on SDS-PAGE, and its enzymatic properties were studied. The results showed that the optimum reaction conditions pH value of ginsenoside Rb3 xylosyl hydrolase was 3.0, which had relatively stable in the range of pH2.2~8.0. The optimum temperature was 40℃, which had better stability in the range of 20~60℃;Metal ion K⁺, Na⁺, Mg²⁺, Mn²⁺, Ca²⁺ ions had no obvious effects on enzyme reaction, and Zn²⁺, Pb²⁺, Ni²⁺ had inhibitory effects on enzyme reaction. The results of SDS-PAGE electrophoresis showed that the molecular weight of enzyme protein was 66.7 kDa. The results of the reaction kinetics showed that the K_m value was 65.63 mmol/L, and V_max was 2.03 mmol/(h·L).The catalytic properties of the enzyme showed that the enzyme could hydrolyze the xyloside of ginsenoside Rb3 into ginsenoside Rd.