title: Thermostable bacterial endoglucanases mined from SWISS-PROT database.
abstract: As one critical enzyme in deconstructing complicated cellulose matrix, endoglucanase (EG) is needed to exhibit high activity and thermostability under severe industrial conditions. Driven by this purpose, EGtf1 (Q08166) and EGtf2 (Q7X2N2), with relatively high specific activities, were selected out of 43 putative EG genes from SWISS-PROT database. These distinguished EGs were successfully overexpressed in Escherichia coli and purified by one-step affinity chromatography. The maximal activity was shown at approximate pH 5.0 and 50 °C. It is worth noting that EGtf1 and EGtf2 displayed outstanding thermostability with a half-life of up to 1,386 h at 50 °C, which is almost 100-fold higher than other reported EGs. Furthermore, the presence of various metal ions (1 mM) or organic solvents (50%, v/v) did not cause significant effect on the activities of EGtf1 and EGtf2 and even showed 2.1- and 2.7-fold enhancement in the case of dodecanol. All these features, especially the excellent thermostability of EGtf1 and EGtf2, enable them to become a good candidate for further protein engineering to realize the ultimate practical application in biomass industry.
authors: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China.
authors: Li-Huan
authors: LH
authors: Qiu
authors: Chun-Xiu
authors: CX
authors: Li
authors: Jie
authors: J
authors: Sun
authors: Zhilong
authors: Z
authors: Wang
authors: Qin
authors: Q
authors: Ye
authors: Jian-He
authors: JH
authors: Xu
mesh_terms: D001419:Bacteria / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002480:Cellulase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D030562:Databases, Protein; D004795:Enzyme Stability; D007700:Kinetics; D008969:Molecular Sequence Data
chemical_list: D001426:Bacterial Proteins; D002480:Cellulase