Abstract:

[Objective] To construct a prokaryotic expression system of type A Clostridium perfringens phage lysin Cp51, and study its antibacterial activity against C. Perfringens type A in vitro.

[Method] Bacteriophage lysin Cp51 gene was synthesized. The prokaryotic expression vector pET-32a-Cp51 was constructed and transformed into Escherichia coli BL21(DE3). After induction using 0.5 mmol·L^–1 IPTG, the soluble recombinant protein Cp51 was successfully expressed, and was subsequently purified with Ni²⁺-NTA affinity chromatography. The antibacterial activity of the recombinant protein Cp51 was detected by kinetic turbidimetric assay.[Result] The bacteria turbidities of seven strains of C. perfringens type A were effectively reduced by the recombinant protein Cp51. The bactericidal rate was above 99.99% in 30 min after treatment of recombinant protein Cp51 at the concentration of above 5 μg·mL^–1. The Cp51 protein had no bactericidal effect against other types of bacteria.[Conclusion] The recombinant protein of bacteriophage lysine Cp51 has strong bactericidal activity and specificity in vitro against type A C. perfringens, which could provide a basis for clinical application of Cp51 lysin.