Characterization Of Different Glycosidases

This paper mainly concerns the purification and reaction characters of dioscin-glycosidase,Astragali-glycosidase and Pulchinenoside-glycosidase which from microorganism Absidia sp.DOd,Absidia sp.A3r and Absidia sp.B00, and ascertains molecular weight, speciality of purified enzyme and kinetics of enzyme reaction.The three glycosidases were pured using DEAE-cellulose column. The pure enzyme purity and molecular weights of the three glycosidases were determined using SDS-polyacrylamide gel electrophoresis to obtain one spot and M.W. of dioscin-glycosidase, Astragali-glycosidase and pulchinenoside-glycosidase were59kDa,54kDa,79kDa.The optimum condition of the three enzymes as follows:Dioscin-glycosidase:pH5.0, the range of stabilization is pH3.0-8.0; temperature,40℃, stable below70℃; It was not effected by K+,Na+, inhibited by Mg2+,Zn2+, Ca2+,Cu2+,Fe3+; The Vmax is1.23mmol/(L-h), the Km is19.26mmol/L.Astragali-glycosidase:pH5.0, the range of stabilization is pH3.0-8.0; temperature,40℃, stable below60℃; It was not effected by Na+,Mg2+, inhibited by K+,Zn2+, Ca2+,Cu2+,Fe3+; The Fmax is1.18mmol/(L-h) the Km is17.86mmol/L.Pulchinenoside-glycosidase:pH5.0, the range of stabilization is pH3.0-8.0; temperature,40℃, stable below50℃; It was not effected by K+,Mg2+, Ca2+and low concentration of Na+, Cu2+,Fe3+, But higher concentration showed inhibitory effect, low concentration of enzyme reaction Zn showed promotion.With the concentration increasing, promotion will change into inhibition.; The Fmax is0.16mmol/(L-h),the Km is7.71mmol/L.The enzyme reaction characteristics of the three glycosidases show that dioscin-glycosidase is capable of hydrolyzing the a-rhamnoside of dioscin and caudaside.Astragali-glycosidase is capable of hydrolyzing the a-rhamnoside of astragali. Pulchinenoside-glycosidase is capable of hydrolyzing the Pulchinenoside.