title: Purification and characterization of xylanase from Aspergillus ficuum AF-98.
abstract: The purification and characterization of xylanase from Aspergillus ficuum AF-98 were investigated in this work. The extracellular xylanase from this fungal was purified 32.6-fold to homogeneity throughout the precipitation with 50-80% (NH(4))(2)SO(4), DEAE-Sephadex A-50 ion exchange chromatography and Sephadex G-100 chromatography. The purified xylanase (specific activity at 288.7 U/ mg protein) was a monomeric protein with a molecular mass of 35.0 kDa as determined by SDS-PAGE. The optimal temperature and pH for the action of the enzyme were at 45 degrees C and 5.0, respectively. The xylanase was activated by Cu(2+) up to 115.8% of activity, and was strongly inhibited by Hg(2+), Pb(2+) up to 52.8% and 89%, respectively. The xylanase exhibited K(m) and V(max) values of 3.267 mg/mL, 18.38 M/min/mg for beechwood xylan and 3.747 mg/mL, 11.1M/min/mg for birchwood xylan, respectively.
authors: Laboratory of Enzyme Engineering, College of Food Science and Technology, Nanjing Agriculture University, Nanjing 210095, China.
authors: Fengxia
authors: F
authors: Lu
authors: Mei
authors: M
authors: Lu
authors: Zhaoxin
authors: Z
authors: Lu
authors: Xiaomei
authors: X
authors: Bie
authors: Haizhen
authors: H
authors: Zhao
authors: Yi
authors: Y
authors: Wang
mesh_terms: D001230:Aspergillus / Q000201:enzymology*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D043364:Endo-1,4-beta Xylanases / Q000302:isolation & purification / Q000378:metabolism*; D005656:Fungal Proteins / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D013816:Thermodynamics; D014934:Wood; D014990:Xylans / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D014990:Xylans; D043364:Endo-1,4-beta Xylanases