The epitope study on the SARS-CoV nucleocapsid protein.
The nucleocapsid protein (N protein) has been found to be an antigenic protein in a number of coronaviruses. Whether the N protein in severe acute respiratory syndrome-associated coronavirus (SARS-CoV) is antigenic remains to be elucidated. Using Western blot and Enzyme-linked Immunosorbent Assay (ELISA), the recombinant N proteins and the synthesized peptides derived from the N protein were screened in sera from SARS patients. All patient sera in this study displayed strong positive immunoreactivities against the recombinant N proteins, whereas normal sera gave negative immunoresponses to these proteins, indicating that the N protein of SARS-CoV is an antigenic protein. Furthermore, the epitope sites in the N protein were determined by competition experiments, in which the recombinant proteins or the synthesized peptides competed against the SARS-CoV proteins to bind to the antibodies raised in SARS sera. One epitope site located at the C-terminus was confirmed as the most antigenic region in this protein. A detailed screening of peptide with ELISA demonstrated that the amino sequence from Codons 371 to 407 was the epitope site at the C-terminus of the N protein. Understanding of the epitope sites could be very significant for developing an effective diagnostic approach to SARS.
Li
Shuting
S
Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300, China.
Lin
Liang
L
Wang
Hao
H
Yin
Jianning
J
Ren
Yan
Y
Zhao
Zhe
Z
Wen
Jie
J
Zhou
Cuiqi
C
Zhang
Xumin
X
Li
Xiaolei
X
Wang
Jingqiang
J
Zhou
Zhengfeng
Z
Liu
Jinxiu
J
Shao
Jianmin
J
Lei
Tingting
T
Fang
Jianqiu
J
Xu
Ningzhi
N
Liu
Siqi
S
D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D006801:Humans; D019590:Nucleocapsid Proteins / Q000737:chemistry / Q000276:immunology*; D010446:Peptide Fragments / Q000138:chemical synthesis; D010957:Plasmids; D011994:Recombinant Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics / Q000276:immunology / Q000378:metabolism*
D000939:Epitopes; D019590:Nucleocapsid Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins