title: Characterization of a novel GH2 family α-L-arabinofuranosidase from hyperthermophilic bacterium Thermotoga thermarum.
abstract: The 2,367-bp ORF of TtAFase from Thermotoga thermarum DSM 5069 encodes a calculated 90-kDa α-L-arabinofuranosidase (TtAFase), which does not belonging to any reported glycosyl hydrolase families α-L-arabinofuranosidases in the database and represents a novel one of glycosyl hydrolase family 2. The purified recombinant TtAFase produced in Escherichia coli BL21 (DE3) had optimum activity at pH 5.5 and at 80 °C. It was stable up to 80 °C and from pH 4.5-8.5. Kinetic experiments at 80 °C with p-nitrophenyl α-L-arabinofuranoside as a substrate gave a K m of 0.77 mM, V max of 2.3 μmol mg(-1) min(-1) and k cat of 4.5 s(-1). The enzyme had no apparent requirement of metal ions for activity, and its activity was significantly inhibited by Cu(2+) or Zn(2+).
authors.affiliation: College of Chemical Engineering, Nanjing Forestry University, Jiangsu Key Lab of Biomass-Based Green Fuels and Chemicals, Nanjing, 210037, Jiangsu, China, ilyshihao@163.com.
authors.forename: Hao
authors.initials: H
authors.lastname: Shi
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Baiyun
authors.initials: B
authors.lastname: Xu
authors.forename: Maobing
authors.initials: M
authors.lastname: Tu
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
mesh_terms: D001089:Arabinose / Q000031:analogs & derivatives; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D003300:Copper / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D004795:Enzyme Stability; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013696:Temperature; D015032:Zinc / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; C017567:4-nitrophenyl-alpha-L-arabinofuranoside; D003300:Copper; D001089:Arabinose; D006026:Glycoside Hydrolases; C019713:alpha-N-arabinofuranosidase; D015032:Zinc