Purification and properties of alpha-galactosidase from Klebsiella Sp. No. PG-2

alpha-Galactosidase has been purified from Klebsiella Sp. No. PG-2, a bacterium isolated from rat small intestine, using calcium phosphate gel, DEAE-cellulose column chromatography and gel filtration technique. About 130-fold increase in specific activity was observed, the pH optimum of 6.5-7.0 characterizes the enzyme as neutral alpha-galactosidase. The optimum temperature was 37 degrees C and the energy of activation was 11,856 cal/mole. Km values obtained for raffinose, mellibose, stachyose and p-nitrophenyl-alpha-D-galactopyranoside were 20.0, 6.6 33.3 and 4.0 mM respectively. The activity was inhibited by p-CMB; iodoacetate, Ag2+, Hg2+, Cu2+, Pb2+ and galactose. Examination of the enzyme activity indicated that the enzyme is cytosolic and is inducible in nature.