SARS冠状病毒N蛋白6个不同原核表达区段的抗原特性分析

目的确定原核表达的SARS—COYN蛋白不同片段抗原特性及在血清学诊断中的应用。方法在前期N蛋白抗原性初步分析的基础上,从39个原核表达不同区段的N蛋白中选取6个纯化的N蛋白即PN360（1—360aa）,PN301（1—301aa）,PN199（30—228aa）,PN185（30—214aa）,PN155b（60—214aa）,PN125（90—214aa）,采用Western—Boh和ELISA方法,检测SARS—COV阴性正常人血清与SARS—COV患者恢复后血清中抗SARS—COVN蛋白抗体。结果Western—Bolt结果表明6个片段皆能与SARS—COV阳性血清反应,但PN360和PN301与SARS—COV阴性血清存在明显交叉反应;使用PN199,PN185,PN155b,PN125作为包被抗原进行ELISA检测,分析表明PN185,PN155b区段的敏感性较好。结论原核表达的SARS—COVN蛋白PN185与PN155b区段是SARS—COV病毒感染的特异性抗体检测的较佳抗原。

Antigenicity characterization of six different fragments of SARS-CoV N protein expressed in E. coli

Objective To determine the antigen characteristics of different fragments of SARS-CoV N protein expressed in E. Coli and their application in the serological diagnosis. Methods Based on preliminary analysis of 39 different segments of the N protein, We choosed six purified N protein for further antigenicity characterization in this study, including that PN360 （ I - 360aa） , PN301 （ 1 - 301aa）, PN199 （30-228aa）, PN185 （30-214aa）, PN155b （60 -214aa）, and PN125 （90 -214aa）. We developed Western-Boh and ELISA to detect antibody reactivity between truncated N fragments with sera from SARS- CoV-negative normal adults or SARS-CoV patient convalescent sera. Results Western-Bolt results show that all the six fragments have reacted with the SARS patient convalescent sera, but the PN360 and PN301 showed obvious cross-reaction with sera from SARS-CoV-negative normal adults; sensitivity analysis using an ELISA coating with PN199, PN185, PN155b, PN125 as antigen showed that the PN185 and PN155b are better than PN125. Conclusion Truncated N protein PN185 and PN155b expressed in E. Coli are better antigen candidates used for detection of SARS-CoV specific antibody.