GroEL‐GroES solubilizes abundantly expressed xylulokinase in Escherichia coli

• Published in: Journal of applied microbiology Vol. 98; no. 1; pp. 210 - 215
• Main Authors: Bu, S., Tsang, P.W.K., Fu, R.Z.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.01.2005; Blackwell Science; Oxford University Press
• Subjects: Bacillus megaterium; Biological and medical sciences; Bioreactors; Chaperonin 10 - metabolism; Chaperonin 60 - metabolism; coexpression; Escherichia coli; Escherichia coli - enzymology; Fermentation; Fundamental and applied biological sciences. Psychology; GroEL‐GroES; insoluble protein; Microbiology; molecular chaperone; Molecular Chaperones; Pentosephosphates - metabolism; Phosphotransferases (Alcohol Group Acceptor) - analysis; Phosphotransferases (Alcohol Group Acceptor) - metabolism; Recombinant Proteins - metabolism; Xylans - metabolism; xylulokinase; Xylulose - metabolism; Xylulokinase; Enzyme; Applied microbiology; Transferases; Chaperone; Escherichia coli; Coexpression; Protein; GroEL-GroES; molecular chaperone; Bacteria; insoluble protein; Enterobacteriaceae
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/j.1365-2672.2004.02446.x

Aims:  The aims of the present work were to solubilize the abundantly expressed recombinant xylulokinase in Escherichia coli and to develop a reliable xylulokinase assay. Methods and Results:  Three mutants of xylulokinase of Bacillus megaterium that were expressed at high level but formed insoluble protein in E. coli BL21(DE3)pLysS were selected for solubility study. The solubility of xylulokinase increased eight to 77‐fold after introduction of molecular chaperones GroEL‐GroES into the host. Conclusion:  This investigation reports that GroEL‐GroES minimizes the formation of insoluble protein in three highly expressed recombinant xylulokinases and an improved xylulokinase assay. Significance and Impact of the Study:  Commercial production of bioethanol is critically dependent on the development of an efficient and low‐cost process of enzymatic conversion of xylan, a major component in lignocellulose biomass, to xylulose‐5‐phosphate, which can then be channelled into pentose phosphate pathway and metabolized to ethanol. The improved intracellular xylulokinase activity is expected to facilitate the xylose degradation.