PURIFICATION AND SOME PHYSICOCHEMICAL CHARACTERISTICS OF BETA-GLUCOSIDASE FROM AFRICAN OIL BEAN (pentaclethra macrophylla

Abstract

p-Glucosidase from African oil bean (Pentaclethra macrophylla) seed was purified at 4°C by two chromatographic steps. The first step involved Ion-exchange

chromatography using DEAE sephadex A-25 and then gel filtration on sephadex G-l 00. A 96 fold purification was obtained. The enzyme was homogeneous as judged by polyacrylamide gel electrophoresis (PAGE) in the presence ofSDS. The enzyme had a specific activity ofO.96Jlmol/mg and molar mass of 26KDa. Its optimum activity was observed at pH 5 and 30°C. The enzyme which was stable at temperatures up to 60°C was gradually inactivated at70°C and above. The enzyme was stable within the pH range of 3-6 at 27°C. The enzyme was activated by Zn2+,Mg2+, Ca2+, Na+ and NH/ while Fe3+ and Cu2+strongly inhibited the enzyme activity. EDT A completely inactivated the enzyme. From Lineweaver-Burk plots, Km and Vmax values found for D-cellobiose were 5.71 mg/ml and 0.12 umol/ml respectively. This work confirms the presence of P-Glucosidase in the African oil bean seed and it is hoped that further work on this enzyme would help to determine its relevance industrially.