N protein of SARS-coronavirus

Abstract 17 Severe acute respiratory syndrome-coronavirus (SARS-CoV) causes an infectious disease through respiratory route. Diagnosing 18 the disease effectively and accurately at early stage is essential for preventing the disease transmission and performing antiviral treat- 19 ment. In this study, we raised monoclonal antibodies (mAbs) against the nucleocapsid (N) protein of SARS-CoV and mapped epi- 20 topes by using different truncated N protein fragments. The mapping of those epitopes was valuable for constructing pair-Abs used 21 in serological diagnosis. The results showed that all of the six raised mAbs were divided into two groups recognizing the region of 22 amino acids 249–317 (A group) or 317–395 (B group). This region spanning amino acids 249–395 contains predominant B cell epi- 23 topes located at the C-terminus of N protein. One pair-Abs, consisting of N protein-specific rabbit polyclonal antibody and SARS- 24 CoV N protein-specific mAb, was selected to construct a sandwich ELISA-kit. The kit was able to specifically detect SARS-CoV N