急性传染性非典型肺炎病毒M蛋白片段抗原性鉴定及其B细胞表位分析

目的:鉴定原核表达的重组急性传染性非典型肺炎(SARS)病毒M蛋白N端1～43氨基酸(aa)的抗原性,并筛选其B细胞表位。方法:GlutathioneSepharose4B亲合层析柱纯化M融合蛋白,用SARS患者恢复期血清分别通过间接ELISA方法和Westernblot鉴定M蛋白片段的抗原性。为了定位B细胞表位,进一步将M蛋白片段截短为部分重叠的2段表达,分别表达含M蛋白N端1～28aa、16～43aa的融合蛋白,通过Westernblot检测B细胞表位所在位置。结果:获得了纯化的M融合蛋白;间接ELISA和Westernblot结果均证实,M蛋白片段有很强的抗原性;并进一步明确B细胞表位位于M蛋白N端1～15aa片段中。结论:原核表达的SARS病毒M蛋白片段N端1～15aa含有一个很强的B细胞表位,这将有助于SARS诊断试剂的研制,也可为多肽疫苗的研制提供帮助。

Identification of the antigenicity of SARS-CoV M protein fragment and analysis of its B-cell antigen epitope

Objective: To identify the antigenicity of N-terminal 1-43 amino acid (aa) of prokaryotic expressed recombinant SARS-CoV M protein, and to screen its B-cell antigen epitope. Methods: The M fusion protein was purified with Glutathione Sepharose 4Baffinity chromatography, and its antigenicity was examined with ELISA and Western blotting using convalescent serum of SARSpatient respectively. In order to screen the site of B-cell epitope, M protein fragment was further expressed with two part-overlappingtruncated protein, which expressed the N-terminal 1-28aa, 16-43aa of M protein respectively, and its B-cell epitope was screened withWestern blotting. Results: The purified M fusion protein was obtained. Indirect ELISA and Western blotting demonstrated that Mprotein fragment was highly antigenic, and its B-cell antigen epitope was located within the N-terminal 1-15aa of M protein.Conclusion: There is a strong B-cell epitope within the N-terminal 1-15aa of M protein, which would lay a foundation of developmentof diagnostic reagent of SARS and multipeptides antigen vaccine.