title: Identification of a conserved epitope cluster in the N protein of porcine reproductive and respiratory syndrome virus.
abstract: In this study, 4 overlapping fragments and 12 overlapping peptides of the nucleocapsid (N) protein from porcine reproductive and respiratory syndrome virus (PRRSV) were expressed as glutathione S-transferase (GST) fusion proteins and used to probe a panel of 16 anti-N protein monoclonal antibodies (mAbs) by ELISA. The minimal epitope sequence of the following seven mAbs was determined by sequential deletion of terminal amino acid residues from each peptide: N2H7 corresponded to H54FPLA58; N2F7 corresponded to K52PHFPLA58; and N1A2, N1E3, N1G4, and N2E5 were reactive against E51KPHFP56. Furthermore, a polypeptide containing this epitope cluster was recognized by PRRSV-immune pig serum by Western blot, suggesting that residues 51-58 represent an immunodominant region of the N protein. Sequence alignment revealed that these epitopes are well conserved among North American and European genotypes of PRRSV. These findings enhance our knowledge of the antigenic structure of N protein and may facilitate the development of better diagnostic methods for PRRSV.
authors.affiliation: National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Zhou
authors.forename: Tong-Qing
authors.initials: TQ
authors.lastname: An
authors.forename: Jin-Xia
authors.initials: JX
authors.lastname: Liu
authors.forename: Hua-Ji
authors.initials: HJ
authors.lastname: Qiu
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Wang
authors.forename: Guang-Zhi
authors.initials: GZ
authors.lastname: Tong
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000097:blood / Q000276:immunology; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D017124:Conserved Sequence; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D007106:Immune Sera / Q000276:immunology; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D013552:Swine
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000939:Epitopes; D007106:Immune Sera; D019590:Nucleocapsid Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins