Obtaining the recombinant fusion protein OprF-aTox of <i>Pseudomonas aeruginosa</i> whith protective properties

Abstract

Into the cells of Escherichia coli (strain BL21(DE3)) two forms of the fusion protein Pseudomonas aeruginosa containing the full length outer membrane protein F (OprF) and nontoxic form of Exotoxin A (without 106 C-terminal amino acid residues) have been synthesized. Two recombinant genes were inserted into plasmid pET28 in different order: oprF-atox and atox-oprF. Only oprF-atox variant allowed to obtain the recombinant protein sufficient for purification by affinity chromatography on Ni-Sepharose. The recombinant fusion protein OprF-aTox showed a high specificity in interaction with the preparations of polyclonal immune rabbit serum to the recombinant OprF, the recombinant nontoxic form of Exotoxin A and the bacterial cells of P. aeruginosa. The purified recombinant fusion protein OprF-aTox after two immunizations protected the mice against toxigenic strain of P. aeruginosa (РА-103) being injected intraperitoneally. The index of efficiency of protective properties of OprF-aTox in the optimal dose (50 µg protein per mouse) was 3.5. This was more efficient than in cases when the recombinant OprF and the recombinant toxoid were injected separately. The indexes of efficiency of protective properties of OprF and the toxoid were 2.1 and 2.0