Figure 2From: High yield production of pigeon circovirus capsid protein in the E. coliby evaluating the key parameters needed for protein expressionEffect of fusion tags, E. coli strains and rare codon replacement on recombinant PiCV capsid protein expression. The three expression plasmids containing wild-type PiCV capsid gene were expressed in E. coli strains BL21 (DE3), BL21 (DE3)-pLysS and BL21 (DE3)-CodonPlus-RIPL. Furthermore, similar plasmids but containing the codon-optimized PiCV capsid gene were also expressed in BL21 (DE3) and BL21 (DE3)-pLysS. All examined recombinant PiCV capsid proteins were analyzed by SDS-PAGE and Western-blotting. Anti-6xHis tag monoclonal antibody was used to recognize the 6xHis-tagged (A) and Trx-tagged (C) Cap proteins. Anti-GST monoclonal antibody was used for detecting GST-tagged (B) Cap proteins. Lane M, pre-stained protein marker; lane 1, 3, 5, 7 and 9, before IPTG induction; lane 2, 4, 6, 8 and 10, after IPTG induction for 4 hrs cultivation. The solid triangle pinpoints the expressed Cap protein.Back to article page