PURIFICATION AND ENZYMATIC-PROPERTIES OF ALPHA-GALACTOSIDASE FROM PENICILLIUM-JANTHINELLUM

Alpha-Galactosidase (E.C.3.2.1.22) from Penicillium janthinellum was p urified by precipitation and fractionation with ammonium sulphate, col d acetone or ethanol, calcium phosphate gel, and column chromatographi es on Sephadex G-100 and G-200. The enzyme was purified about 110.39-f old when Sephadex G-100 was used. Alpha-Galactosidase exhibited the op timum pH and temperature at 4.5 and 60-degrees-C, respectively. The op timum enzyme stability was obtained at pH 3.5 for 24 h (at room temper ature). The enzyme was found to be thermostable below 65-degrees-C up to 40 minutes and was gradually inactivated by increasing the temperat ure above this degree. The MICHAELis constant was 0.55 mM for p-nitrop henyl-alpha-D-galactoside. The alpha-galactosidase activity was strong ly inhibited by Hg++ and slightly activated by Mn++. The results show the possibility of producing a thermostable enzyme from a low-priced a gricultural product, for instance, lupine.