PURIFICATION AND CHARACTERIZATION OF AN INTRACELLULAR ALPHA-D-XYLOSIDASE FROM PENICILLIUM-WORTMANNII IFO-7237

Intracellular alpha-D-xylosidase from Penicillium wortmannii IFO 7237 was obtained by grinding the mold with almina in phosphate buffer, and the cell-free extract was purified to a homogeneous state on SDS-poly acrylamide gel electrophoresis (SDS-PAGE), The molecular weight was es timated to be 290,000 by gel filtration chromatography (Superdex 200) and 73,000 was obtained by SDS-PAGE, The purified alpha-xylosidase had an isoelectric point at pH 5.0, The optimum activity for the enzyme w as found to be at pH 6.5 and 45 degrees C. The enzyme showed a hydroly tic activity on p-NO2-phenyl-alpha-D-xylopyranoside (alpha-p-NPX) whil e methyl-alpha-D-xylopyranoside (alpha-MX) was not hydrolyzed at all, It also showed lower activity for xyloglucan oligosaccharides, The app arent K-m values of the enzyme for alpha-p-NPX and isoprimeverose were 1.9 mM and 50 mM, respectively.