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Optimized E. coli expression strain LOBSTR eliminates common contaminants from His‐tag purification
Author(s) -
Andersen Kasper R.,
Leksa Nina C.,
Schwartz Thomas U.
Publication year - 2013
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.24364
Subject(s) - escherichia coli , strain (injury) , recombinant dna , chemistry , histidine , contamination , protein expression , target protein , protein purification , chromatography , affinity chromatography , biochemistry , biology , gene , amino acid , enzyme , ecology , anatomy
His‐tag affinity purification is one of the most commonly used methods to purify recombinant proteins expressed in E. coli . One drawback of using the His‐tag is the co‐purification of contaminating histidine‐rich E. coli proteins. We engineered a new E. coli expression strain, LOBSTR ( lo w b ackground str ain), which eliminates the most abundant contaminants. LOBSTR is derived from the E. coli BL21(DE3) strain and carries genomically modified copies of arnA and slyD , whose protein products exhibit reduced affinities to Ni and Co resins, resulting in a much higher purity of the target protein. The use of LOBSTR enables the pursuit of challenging low‐expressing protein targets by reducing background contamination with no additional purification steps, materials, or costs, and thus pushes the limits of standard His‐tag purifications. Proteins 2013; 81:1857–1861. © 2013 Wiley Periodicals, Inc.