title: Characterization of a recombinant bifunctional xylosidase/arabinofuranosidase from Phanerochaete chrysosporium.
abstract: A bifunctional xylosidase/arabinofuranosidase gene (PcXyl) was cloned from the cDNA library of Phanerochaete chrysosporium and further expressed in Pichia pastoris. Enzymatic assay indicated that P. pastoris produced rPcXyl at a level of 26,141 U l⁻¹. The xylosidase and arabinofuranosidase activities of rPcXyl were maximized, respectively, at pHs of 5.0 and 5.5 and temperatures of 45°C and 50°C. SDS-PAGE revealed a single band of purified rPcXyl of 83 kDa. Cu²⁺ and Zn²⁺ completely inhibited the enzyme activity of rPcXyl. The enzyme activity of rPcXyl was increased 151%, 126% and 123%, respectively, in the presence of glucose, xylose and arabinose at concentrations of 5 mM. rPcXyl hydrolyzed xylobiose to xylose and xylotriose to xylose and xylobiose, indicating rPcXyl acts as an exo-type enzyme. Additionally, rPcXyl enhanced xylose release from xylan substrates in synergy with rPcXynC.
authors.affiliation: Division of Biotechnology, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan, Jeonbuk 570-752, Republic of Korea.
authors.forename: Nguyen Duc
authors.initials: ND
authors.lastname: Huy
authors.forename: Palvannan
authors.initials: P
authors.lastname: Thayumanavan
authors.forename: Tae-Ho
authors.initials: TH
authors.lastname: Kwon
authors.forename: Seung-Moon
authors.initials: SM
authors.lastname: Park
mesh_terms: D000595:Amino Acid Sequence; D001089:Arabinose / Q000235:genetics; D003001:Cloning, Molecular; D004187:Disaccharides / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D020075:Phanerochaete / Q000201:enzymology* / Q000235:genetics; D010843:Pichia / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D014990:Xylans / Q000378:metabolism; D014994:Xylose / Q000378:metabolism; D014995:Xylosidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D004187:Disaccharides; D011994:Recombinant Proteins; D014990:Xylans; D014994:Xylose; D001089:Arabinose; D006026:Glycoside Hydrolases; D014995:Xylosidases; C026579:exo-1,4-beta-D-xylosidase; C019713:alpha-N-arabinofuranosidase; C004173:xylobiose