title: Construction and characterization of different fusion proteins between cellulases and β-glucosidase to improve glucose production and thermostability.
abstract: A β-glucosidase from Clostridium cellulovorans (CcBG) was fused with one of three different types of cellulases from Clostridium thermocellum, including a cellulosomal endoglucanase CelD (CtCD), a cellulosomal exoglucanase CBHA (CtCA) and a non-cellulosomal endoglucanase Cel9I (CtC9I). Six bifunctional enzymes were constructed with either β-glucosidase or cellulase in the upstream. CtCD-CcBG showed the favorable specific activities on phosphoric acid swollen cellulose (PASC), an amorphous cellulose, with more glucose production (2 folds) and less cellobiose accumulation (3 folds) when compared with mixture of the single enzymes. Moreover, CtCD-CcBG had significantly improved thermal stability with a melting temperature (T(m)) of 10.9°C higher than that of CcBG (54.5°C) based on the CD unfolding experiments. This bifunctional enzyme is thus useful in industrial application to convert cellulose to glucose.
authors.affiliation: Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Hsiao-Lin
authors.initials: HL
authors.lastname: Lee
authors.forename: Chih-Kang
authors.initials: CK
authors.lastname: Chang
authors.forename: Kuo-Hsun
authors.initials: KH
authors.lastname: Teng
authors.forename: Po-Huang
authors.initials: PH
authors.lastname: Liang
mesh_terms: D056804:Biofuels; D018533:Biomass; D002480:Cellulase / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry; D046974:Clostridium cellulovorans / Q000201:enzymology*; D048013:Acetivibrio thermocellus / Q000201:enzymology; D004926:Escherichia coli / Q000201:enzymology; D005947:Glucose / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D011994:Recombinant Proteins / Q000737:chemistry; D013696:Temperature; D001617:beta-Glucosidase / Q000737:chemistry*
chemical_list: D056804:Biofuels; D011994:Recombinant Proteins; D002482:Cellulose; C087879:endoglucanase CelD; D001617:beta-Glucosidase; D002480:Cellulase; D005947:Glucose