衣原体噬菌体phiCPG1衣壳蛋白Vp1蛋白IN5部分的克隆、表达、鉴定及其对沙眼衣原体抑制作用的研究

Cloning, expressing and identifying of IN5 part of chlamydiaphage phiCPG1 capsid protein Vp1 protein and its inhibitory effect on the Chlamydia trachomatis

目的 探讨衣原体噬菌体phiCPG1衣壳蛋白Vp1蛋白IN5部分在Vp1抑制沙眼衣原体（Chlamydia trachomatis,Ct）生长过程中的作用.方法 以Vp1质粒为模板,PCR扩增IN5环基因片段,构建重组质粒pET28a/IN5,转化后诱导表达鉴定,收集纯化的IN5蛋白.将IN5蛋白、Vp1蛋白及各对照组作用于Ct培养过程中,48 h后碘染色及间接免疫荧光进行包涵体计数,采用单因素方差分析比较各组间包涵体均数的差异,若各组均数间差异有统计学意义,采用Bonferroni法对任两个均数进行比较,最后计算IN5蛋白和Vp1蛋白对Ct的抑制率.结果 成功地诱导表达出Vp1蛋白的IN5部分,并发现在浓度均为53 μg/mL时,IN5蛋白对Ct的抑制率为52.42%,而Vp1的抑制率为78.04%.结论 IN5蛋白同样对Ct生长有抑制作用,但较Vp1弱,这为寻找Vp1蛋白抑制Ct生长的优势蛋白区域提供了初步探索的经验.

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.