结核分枝杆菌Rv3873抗原表位预测及其蛋白片段抗原性研究

Epitope prediction of Rv3873 gene from Mycobacterium tuberculosis and antigenicity analysis of related protein fragments

目的对结核分枝杆菌Rv3873进行生物信息学分析及抗原表位预测,原核表达Rv3873基因21～235位氨基酸蛋白片段,命名为Rv387321～235重组蛋白,初步分析其抗原性。方法 PCR扩增结核分枝杆菌Rv3873 21～235位氨基酸的基因片段,构建其原核表达载体,转化大肠杆菌BL21(DE3),获得重组蛋白并纯化;采用酶联免疫吸附试验(ELISA)对Rv387321～235重组蛋白进行抗原性检测。结果具有优势抗原表位的Rv3873蛋白片段在大肠杆菌中高效表达;ELISA结果显示,Rv387321～235重组蛋白在结核病检测中的敏感性为28%,特异性94.6%。结论生物信息学预测Rv3873基因抗原表位,为寻找有价值的抗原靶点提供了参考;具有优势抗原表位的重组蛋白片段在结核病诊断中具有潜在应用价值,可作为联合诊断的备选抗原之一。

Objective To analyze and predict the epitope of Rv3873 in Mycobacterium tuberculosis,to express the 21-235 amino acid fragment of Rv3873 in prokaryotic vectors,named Rv387321-235 recombinant protein,and to analyze its antigenicity.Methods The gene of the 21-235 amino acid fragment from M.tuberculosis Rv3873 was amplified by PCR.Prokaryotic expression vectors of Rv387321-235 recombinant protein were constructed,and subsequently transformed into E.coli BL21（DE3）.Recombinant protein was purified and its antigenicity was detected by ELISA.Results The Rv3873 protein fragments with a dominant epitope were expressed effectively in E.coli.The ELISA results showed certain sensibility（28%） and high specificity（94.6%） when Rv387321-235 recombinant protein was used as an antigen for tuberculosis diagnosis.Conclusion The epitope of Rv3873 by bioinformatics prediction,helps to find a better target site of antigens and can be used as candidate antigens in the diagnosis of tuberculosis.