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Expression and characterization of a cold-active and xylose-stimulated β-glucosidase from Marinomonas MWYL1 in Escherichia coli.

Research paper by Wei W Zhao, Rihe R Peng, Aisheng A Xiong, Xiaoyan X Fu, Yongsheng Y Tian, Quanhong Q Yao

Indexed on: 18 Jun '11Published on: 18 Jun '11Published in: Molecular Biology Reports



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.