[Bacterial expression, preparation and identification of polyclonal antibody against Escherichia coli FtsZ].

To prepare polyclonal antibody (PcAb) against Escherichia coli filamentous thermosensitive protein Z (Ec-FtsZ), the artificially synthesized gene fragment coding Ec-FtsZ was subcloned into pET-22b(+) plasmid, and Ec-FtsZ protein was expressed in E. coli BL21(DE3) cell under an optimal bacterial expression condition. Then Ec-FtsZ protein was purified by HisTrap affinity chromatography, and the GTPase (Guanosine triphosphatase) activity of purified Ec-FtsZ protein was further analyzed by malachite green assay. Subsequently, the purified Ec-FtsZ protein was used to immunize rat subcutaneously for preparation of anti-Ec-FtsZ PcAb. The results of enzyme-linked immunosorbent assay (ELISA), Western blotting analysis and immunofluorescence assay showed that the titer of PcAb was 1:256 000, and PcAb exhibited a perfect antigenic specificity against purified and endogenous Ec-FtsZ protein. All these data indicated that the anti-Ec-FtsZ PcAb is successfully prepared, which can be used for further cellular function study and biochemical analysis of Ec-FtsZ protein in vivo.