title: The epitope structure of Citrus tristeza virus coat protein mapped by recombinant proteins and monoclonal antibodies.
abstract: It has been known that there exists serological differentiation among Citrus tristeza virus (CTV) isolates. The present study reports three linear epitopes (aa 48-63, 97-104, and 114-125) identified by using bacterially expressed truncated coat proteins and ten monoclonal antibodies against the native virions of CTV-S4. Site-directed mutagenesis analysis demonstrated that the mutation D98G within the newly identified epitope (97)DDDSTGIT(104) abolished its reaction to MAbs 1, 4, and 10, and the presence of G98 in HB1-CP also resulted in its failure to recognize the three MAbs. Our results suggest that the conformational differences in the epitope I (48)LGTQQNAALNRDLFLT(63) between the CPs of isolates S4 and HB1 might contribute to the different reactions of two isolates to MAbs 5 and 6. This study provides new information for the antigenic structures of CTV, and will extend the understanding of the processes required for antibody binding and aid the development of epitope-based diagnostic tools.
authors: National Key Laboratory of Agromicrobiology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China.
authors: Guan-Wei
authors: GW
authors: Wu
authors: Min
authors: M
authors: Tang
authors: Guo-Ping
authors: GP
authors: Wang
authors: Cai-Xia
authors: CX
authors: Wang
authors: Yong
authors: Y
authors: Liu
authors: Fan
authors: F
authors: Yang
authors: Ni
authors: N
authors: Hong
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology*; D036022:Capsid Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D002957:Citrus / Q000821:virology*; D017790:Closterovirus / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D018604:Epitope Mapping; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000821:virology*
chemical_list: D000911:Antibodies, Monoclonal; D036022:Capsid Proteins; C068839:coat protein, citrus tristeza virus
keywords: Citrus tristeza virus; Coat protein; Epitope mapping; Monoclonal antibody; Recombinant protein; Structure analysis