Identification of an epitope of SARS-coronavirus nucleocapsid protein

LIN, Ying; SHEN, Xu; YANG, Rui Fu; LI, Yi Xue; JI, Yong Yong; HE, You Yu; SHI, Mu De; LU, Wei; SHI, Tie Liu; WANG, Jin; WANG, Hong Xia; JIANG, Hua Liang; SHEN, Jian Hua; XIE, You Hua; WANG, Yuan; PEI, Gang; SHEN, Bei Fen; WU, Jia Rui; SUN, Bing

The nucleocapsid (N) protein of severe acute respiratory syndrome-coronavirus (SARS-CoV) is a major virion structural protein. In this study, two epitopes (N1 and N2) of the N protein of SARS-CoV were predicted by bioinformatics analysis. After immunization with two peptides, the peptides-specific antibodies were isolated from the immunized rabbits. The further experiments demonstrated that N1 peptide-induced polyclonal antibodies had a high affinity to bind to E. coli expressed N protein of SARS-CoV. Furthermore, it was confirmed that N1 peptide-specific IgG antibodies were detectable in the sera of severe acute respiratory syndrome (SARS) patients. The results indicated that an epitope of the N protein has been identified and N protein specific Abs were produced by peptide immunization, which will be useful for the study of SARS-CoV.