title: Expression and characterization of a cold-active and xylose-stimulated β-glucosidase from Marinomonas MWYL1 in Escherichia coli.
abstract: The gene encoding a cold-active and xylose-stimulated β-glucosidase of Marinomonas MWYL1 was synthesized and expressed in Escherichia coli. The recombinant enzyme (reBglM1) was purified and characterized. The molecular mass of the purified reBglM1 determined by SDS-PAGE agree with the calculated values (50.6 Da). Optima of temperature and pH for enzyme activity were 40 °C and 7.0, respectively. The enzyme exhibited about 20% activity at 5 °C and was stable over the range of pH 5.5-10.0. The presence of xylose significantly enhanced enzyme activity even at higher concentrations up to 600 mM, with maximal stimulatory effect (about 1.45-fold) around 300 mM. The enzyme is active with both glucosides and galactosides and showed high catalytic efficiency (k (cat) = 500.5 s(-1)) for oNPGlc. These characterizations enable the enzyme to be a promising candidate for industrial applications.
authors.affiliation: Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, 2901 Beidi Road, Shanghai 201106, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Rihe
authors.initials: R
authors.lastname: Peng
authors.forename: Aisheng
authors.initials: A
authors.lastname: Xiong
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Fu
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Tian
authors.forename: Quanhong
authors.initials: Q
authors.lastname: Yao
mesh_terms: D001483:Base Sequence; D003080:Cold Temperature; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D053544:Marinomonas / Q000201:enzymology*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D014994:Xylose / Q000378:metabolism; D001617:beta-Glucosidase / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D011994:Recombinant Proteins; D014994:Xylose; D001617:beta-Glucosidase