中国生物工程杂志

Objective To clone lexA gene, express and purify the repressor LexA from Pseudomonas aeruginosa (PA), prepare the polyclonal antibody against PC-1 protein in rabbits, detect immunological activity of LexA protein. Methods The genomic DNA was extracted from the PAO1, the gene fragment was encoding the mature LexA was amplied by PCR. It was linked the vector pET32a(+) and expressed in the E.coli BL21(DE3).The expressed protein was purified by two steps of Ni2+ chelate affinity chromatography and gel filtration chromatography respectively. The purified LexA protein immune the rabbits by injection and prepare the polyclonal antibody against PC-1 protein. The immunological activity of expressed and purified LexA protein was detected by ELISA , and Western blot. Results The expressed fused protein was found in insoluble form, accounted for 45% of the total bacteria protein. The final purity was 98.97%, which was determined by the HPLC. The expressed and purified LexA protein had satisfactory immunological activity.