[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 (1 -360aa), PN301 (1-301aa), PN199 (30-228aa), PN185 (30-214aa), PN155b (60-214aa), and PN125 (90-214aa). We developed Western-Bolt 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.


CONCLUSIONS
Truncated N protein PN185 and PN155b expressed in E. Coli are better antigen candidates used for detection of SARS-CoV specific antibody.
National Institute for Viral Disease Control and Prevention, State Key Laboratory for Molecular Virology and Genetic Engineering, Chinese Center for Disease Control and Prevention, Beijing 102206 China.
Hui-Juan
HJ
Wang
Wei-Min
WM
Zhou
Lin-Ling
LL
Zhang
Li
L
Ruan
Ning-Shao
NS
Xia
Wen-Jie
WJ
Tan
D000914:Antibodies, Viral / Q000097:blood*; D015153:Blotting, Western; D000086462:Coronavirus Nucleocapsid Proteins; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D019590:Nucleocapsid Proteins / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D012698:Serologic Tests; D045169:Severe Acute Respiratory Syndrome / Q000175:diagnosis
D000914:Antibodies, Viral; D000086462:Coronavirus Nucleocapsid Proteins; D019590:Nucleocapsid Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins