ABSTRACT
Objective To investigate the inhibitory effect of IN5 from chlamydiaphage phiCPG1 capsid protein Vp1 on Chlamydia trachomatis (Ct).Methods PCR was used to amplify IN5 gene from Vp1 DNA of phiCPG1, then the recombinant plasmid pET28a/IN5 was constructed.After transformation, the fusion protein IN5 was induced,identified and purified.Ct was incubated with the purified IN5 protein or Vp1 protein.After 48 h of incubation, the inclusion bodies were counted with iodine staining and indirect immunofluorescence.One-way ANOVA was used to compare the difference of inclusion bodies among groups.If the difference among the groups was statistically significant, the Bonferroni method was used to compare any two mean values.Finally, the inhibitory rate of IN5 protein and Vp1 protein to Ct was calculated.Results IN5 protein from chlamydiaphage phiCPG1 capsid protein Vp1 was successfully obtained.At the same concentration of 53μg/mL,the inhibitory rates of Ct growth in IN5 and in Vp1 groups were 52.42% and 78.04%, respectively.Conclusion IN5 protein has inhibitory effect on the growth of Ct,but the inhibitory rate is lower than that of Vp1, which provides a preliminary clue for searching the dominant region of Vp1 protein inhibiting the growth of Ct.