title: Purification and characterization of an intracellular alpha-D-xylosidase from Penicillium wortmannii IFO 7237.
abstract: 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-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight was estimated to be 290,000 by gel filtration chromatography (Superdex 200) and 73,000 was obtained by SDS-PAGE. The purified alpha-D-xylosidase had an isoelectric point at pH 5.0. The optimum activity for the enzyme was found to be at pH 6.5 and 45 degrees C. The enzyme showed a hydrolytic activity on p-NO2-phenyl-alpha-D-xylopyranoside (alpha-p-NPX) while methyl-alpha-D-xylopyranoside (alpha-MX) was not hydrolyzed at all. It also showed lower activity for xyloglucan oligosaccharides. The apparent Km values of the enzyme for alpha-p-NPX and isoprimeverose were 1.9 mM and 50 mM, respectively.
authors.affiliation: Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Matsuo
authors.forename: T
authors.initials: T
authors.lastname: Seki
authors.forename: Y
authors.initials: Y
authors.lastname: Mitsuishi
authors.forename: H
authors.initials: H
authors.lastname: Shoun
authors.forename: T
authors.initials: T
authors.lastname: Nakahara
mesh_terms: D005936:Glucans; D009844:Oligosaccharides / Q000378:metabolism; D010407:Penicillium / Q000201:enzymology*; D011134:Polysaccharides / Q000378:metabolism; D013379:Substrate Specificity; D014990:Xylans; D014995:Xylosidases / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D005936:Glucans; D009844:Oligosaccharides; D011134:Polysaccharides; D014990:Xylans; C029353:xyloglucan; D014995:Xylosidases; C047831:alpha-D-xylosidase