title: Peptide-binding motif prediction by using phage display library for SasaUBA*0301, a resistance haplotype of MHC class I molecule from Atlantic Salmon (Salmo salar).
abstract: The structure of the peptide-binding specificity of major histocompatibility complex (MHC) class I has been analyzed extensively in human and mouse. For fish, there are no crystallographic models of MHC molecules, neither are there data on the peptide-binding specificity. In this study, we describe for the first time the identification of a fish class I peptide-MHC ligand binding motif. Phage display technology using both 7 mer and 12 mer libraries enabled us to identify peptide ligands with unique specificity that interacts with the recombinant Salmon MHC class I molecule. The recombinant proteins, beta 2m/SasaUBA*0301, were produced in Escherichia coli, in which the carboxyl terminus of beta 2-microglobulin is joined together with a flexible (GGGGS)3 linker to the amino terminus of the heavy chain. One hundred and seven individual phages bound to beta 2m/SasaUBA*0301 were isolated after four rounds of panning from the 7 mer random-peptide library. The peptide encoding sequences were determined and peptide alignment led to the prediction of position-specific anchor residue. A prominent proline at position 2 was observed and we predict that it might be one of the anchors at the N-terminus. Meanwhile, phage display peptide library encoding random 12 mer peptides was also screened against beta 2m/SasaUBA*0301. Eighty-five percentages of the corresponding peptides have an enrichment of leucine, methionine, valine, or isoleucine at the C-terminus. We predict that this particular allele of Salmon class I molecule might have a very similar binding motif at the C-terminus compared with a known mouse class I molecule H2-Kb which has L, or I, V, M at p8. Previous work showed that Atlantic Salmon carrying the allele SasaUBA*0301 are resistant to infectious Salmon aneamia virus and there is a significant association between MHC polymorphism and the disease resistance. Therefore, our study might contribute to designing a peptide vaccine against this viral disease.
authors.affiliation: Department of Food Science and Nutritional Engineering, China Agricultural University, 100083 Beijing, PR China. hengzhao2000@gmail.com <hengzhao2000@gmail.com>
authors.forename: Heng
authors.initials: H
authors.lastname: Zhao
authors.forename: Trudi
authors.initials: T
authors.lastname: Hermsen
authors.forename: Rene J M
authors.initials: RJ
authors.lastname: Stet
authors.forename: Karsten
authors.initials: K
authors.lastname: Skjødt
authors.forename: Huub F J
authors.initials: HF
authors.lastname: Savelkoul
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000276:immunology* / Q000378:metabolism; D007113:Immunity, Innate; D046829:Isavirus / Q000276:immunology; D019151:Peptide Library; D010455:Peptides / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000276:immunology; D020317:Salmo salar / Q000276:immunology*; D016415:Sequence Alignment
chemical_list: D015395:Histocompatibility Antigens Class I; D019151:Peptide Library; D010455:Peptides; D011994:Recombinant Proteins