Purification and some properties of a beta-xylosidase and an alpha-fucosidase from apple snails (Pomacea canaliculata).

beta-Xylosidase and alpha-fucosidase were purified from the viscera of apple snails (Pomacea canaliculata) using ammonium sulfate precipitation, hydrophobic chromatography on Butyl-Toyopearl, gel filtration on Sephacryl S-300, and Q-Sepharose column chromatography. beta-Xylosidase and alpha-fucosidase are glycoproteins and their molecular masses were estimated to be approximately 85 kDa and 54 kDa by SDS-polyacrylamide gel electrophoresis, and assumed to be about 96 kDa and 230 kDa from their sedimentation coefficients, respectively, indicating that the former is a monomer and the latter has a tetrameric structure. beta-Xylosidase is stable at pH 4-10 and its optimum pH toward pNP-beta-D-xyloside is around 3.6, while alpha-fucosidase is fairly stable at 65 degrees C and pH 4-10, and its optimum pHs toward pNP-alpha-L-fucoside are around 3.2 and 5.2. beta-Xylosidase released a xylose residue from Xylbeta1->2Manbeta1->4GlcNAcbeta1->4(Fucalpha1-> 3)GlcNAc-PA and Manalpha1->6(Manalpha1->3)(Xylbeta1->2)Manbeta1- >4GlcNAcbeta1->4(Fucalpha1->3)GlcNAc-PA, but not from GlcNAcbeta1->2Manalpha1->6(GlcNAcbeta1->2Manalpha1+ ++->3)(Xylbeta1->2)Manbeta1->4GlcNAcbeta1-> 4(Fucalpha1->3)GlcNAc-PA, while alpha-fucosidase released a fucose residue from these three PA-oligosaccharides.