Expression, Purification Of The Heat Shock Protein GrpE From Streptococcus Pneumonia And Research Of Its Thermal Stabilit

Objective The heat shock protein GrpE is a component of the HSP70, Which is contact with a negative regulator of heat shock gene expression. To uncover the infectious mechanism, we expressed and purified the heat shock protein GrpE from Streptococcus pneumonia.Methods Being amplified by PCR, the open reading frame of GrpE was subcloned into pW28 and expressed in E coli B834. The bacterial protein was purified by nickel chromatography column, anion-exchange chromatography column (DEAE) and gel filtration column (Superdex 75). Thermal stability was characterized with TS A method.Results The GrpE protein was expressed in E.coli B834 as soluble. The purified protein with high purity of 95% exhibits homodimer in solutions. The recombinant GrpE protein presents relative stabilization in a solution at pH 6.0 and 20mM NaCl. Crystallization optimization were obtained single crystals that grew in 20mM (NH4)2SO4,25% PEG3350,0.1 mol/L Bis-Tris pH 6.0, within 10 d.Conclusions This is the first report that the GrpE protein with high purity was expressed in E.coli B834 and its thermal stability was determined with TS A method.