title: Biochemical characterization of a thermostable β-1,3-xylanase from the hyperthermophilic eubacterium, Thermotoga neapolitana strain DSM 4359.
abstract: The biochemical properties of a putative β-1,3-xylanase from the hyperthermophilic eubacterium Thermotoga neapolitana DSM 4359 were determined from a recombinant protein (TnXyn26A) expressed in Escherichia coli. This enzyme showed specific hydrolytic activity against β-1,3-xylan and released β-1,3-xylobiose and β-1,3-xylotriose as main products. It displayed maximum activity at 85 °C during a 10-min incubation, and its activity half-life was 23.9 h at 85 °C. Enzyme activity was stable in the pH range 3-10, with pH 6.5 being optimal. Enzyme activity was significantly inhibited by the presence of N-bromosuccinimide (NBS). The insoluble β-1,3-xylan K m value was 10.35 mg/ml and the k cat value was 588.24 s(-1). The observed high thermostability and catalytic efficiency of TnXyn26A is both industrially desirable and also aids an understanding of the chemistry of its hydrolytic reaction.
authors.affiliation: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Okazaki
authors.forename: Nanami
authors.initials: N
authors.lastname: Nakashima
authors.forename: Chiaki
authors.initials: C
authors.lastname: Ogino
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tamaru
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D055162:Biocatalysis; D017931:DNA Primers; D004795:Enzyme Stability; D006868:Hydrolysis; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D046949:Thermotoga neapolitana / Q000201:enzymology*; D043325:Xylan Endo-1,3-beta-Xylosidase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D043325:Xylan Endo-1,3-beta-Xylosidase