Functionally active rat S100A4 from a polymerase chain reaction-synthesized gene expressed in soluble form in Escherichia coli

Three Novel Escherichia coli Vectors for Convenient and Efficient Molecular Biological Manipulations

We have constructed novel plasmids pANY2, pANY3, and pANY6 for flexible cloning with low false positives, efficient expression, and convenient purification of proteins. The pANY2 plasmid can be used for efficient isopropyl-β-d-thiogalactoside (IPTG) induced protein expression, while the pANY3 plasmid can be used for temperature-induced expression. The pANY6 plasmid contains a self-cleaving elastin-like protein (ELP) tag for purification of recombinant protein by simple ELP-mediated precipitation steps and removal of the ELP tag by self-cleavage. A urea-based denaturation and refolding processes for renaturation of insoluble inclusion bodies can be conveniently integrated into the ELP-mediated precipitation protocol, removing time-consuming dialysis steps. These novel vectors, together with the described strategies of gene cloning, protein expression, and purification, may have wide applications in biosciences, agricultural, food technologies, and so forth.