title: Identification of a Conserved Linear B-Cell Epitope of Streptococcus dysgalactiae GapC Protein by Screening Phage-Displayed Random Peptide Library.
abstract: The GapC of Streptococcus dysgalactiae (S. dysgalactiae) is a highly conserved surface protein that can induce protective humoral immune response in animals. However, B-cell epitopes on the S. dysgalactiae GapC have not been well identified. In this study, a monoclonal antibody (mAb5B7) against the GapC1-150 protein was prepared. After passive transfer, mAb5B7 could partially protect mice against S. dysgalactiae infection. Eleven positive phage clones recognized by mAb5B7 were identified by screening phage-displayed random 12-peptide library, most of which matched the consensus motif DTTQGRFD. The motif sequence exactly matches amino acids 48-55 of the S. dysgalactiae GapC protein. In addition, the motif 48DTTQGRFD55 shows high homology among various streptococcus species. Site-directed mutagenic analysis further confirmed that residues D48, T50, Q51, G52 and F54 formed the core motif of 48DTTQGRFD55. This motif was the minimal determinant of the B-cell epitope recognized by the mAb5B7. As expected, epitope-peptide evoked protective immune response against S. dysgalactiae infection in immunized mice. Taken together, this identified conserved B-cell epitope within S. dysgalactiae GapC could provide very valuable insights for vaccine design against S. dysgalactiae infection.
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Limeng
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Ziyao
authors.initials: Z
authors.lastname: Fan
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Xue
authors.initials: X
authors.lastname: Zhou
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Liquan
authors.initials: L
authors.lastname: Yu
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Hunan
authors.initials: H
authors.lastname: Sun
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Wu
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Yongzhong
authors.initials: Y
authors.lastname: Yu
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Baifen
authors.initials: B
authors.lastname: Song
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Jinzhu
authors.initials: J
authors.lastname: Ma
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Chunyu
authors.initials: C
authors.lastname: Tong
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Xintong
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Animal Science and Veterinary Medicine, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Zhanbo
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China; College of Animal Science and Veterinary Medicine, HeiLongJiang BaYi Agricultural University, Daqing, P. R. China.
authors.forename: Yudong
authors.initials: Y
authors.lastname: Cui
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000942:Antigens, Bacterial / Q000737:chemistry / Q000276:immunology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology*; D002999:Clone Cells; D017124:Conserved Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry* / Q000276:immunology*; D057927:Hydrophobic and Hydrophilic Interactions; D007109:Immunity; D007114:Immunization; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D019151:Peptide Library; D018583:Pliability; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification; D016415:Sequence Alignment; D013291:Streptococcus / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D018985:Epitopes, B-Lymphocyte; C469817:GapC protein, Streptococcus; D019151:Peptide Library; D011993:Recombinant Fusion Proteins