Engineering Escherichia coli BL21(DE3) derivative strains to minimize E. coli protein contamination after purification by immobilized metal affinity chromatography.

ABSTRACT: Recombinant His-tagged proteins expressed in Escherichia coli and purified by immobilized metal affinity chromatography (IMAC) are commonly coeluted with native E. coli proteins, especially if the recombinant protein is expressed at a low level. The E. coli contaminants display high affinity to divalent nickel or cobalt ions, mainly due to the presence of clustered histidine residues or biologically relevant metal binding sites. To improve the final purity of expressed His-tagged protein, we engineered E. coli BL21(DE3) expression strains in which the most recurring contaminants are either expressed with an alternative tag or mutated to decrease their affinity to divalent cations. The current study presents the design, engineering, and characterization of two E. coli BL21(DE3) derivatives,

SUBMITTER: Robichon C 

PROVIDER: S-EPMC3127686 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature