title: A structure-based strategy for epitope discovery in Burkholderia pseudomallei OppA antigen.
abstract: We present an approach integrating structural and computational biology with immunological tests to identify epitopes in the OppA antigen from the Gram-negative pathogen Burkholderia pseudomallei, the etiological agent of melioidosis. The crystal structure of OppA(Bp), reported here at 2.1 Å resolution, was the basis for a computational analysis that identified three potential epitopes. In parallel, antigen proteolysis and immunocapturing allowed us to identify three additional peptides. All six potential epitopes were synthesized as free peptides and tested for their immunoreactivity against sera from healthy seronegative, healthy seropositive, and recovered melioidosis patients. Three synthetic peptides allowed the different patient groups to be distinguished, underlining the potential of this approach. Extension of the computational analysis, including energy-based decomposition methods, allowed rationalizing results of the predictive analyses and the immunocapture epitope mapping. Our results illustrate a structure-based epitope discovery process, whose application may expand our perspectives in the diagnostic and vaccine design fields.
authors.affiliation: Department of Biosciences, University of Milan, Milan 20133, Italy.
authors.forename: Patricia
authors.initials: P
authors.lastname: Lassaux
authors.affiliation: Consiglio Nazionale delle Ricerche, Institute for Chemistry of Molecular Recognition, Department of Computational Biology, Milan 20131, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Peri
authors.affiliation: Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain.
authors.forename: Mario
authors.initials: M
authors.lastname: Ferrer-Navarro
authors.affiliation: Department of Biosciences, University of Milan, Milan 20133, Italy.
authors.forename: Louise J
authors.initials: LJ
authors.lastname: Gourlay
authors.affiliation: Consiglio Nazionale delle Ricerche, Institute for Chemistry of Molecular Recognition, Department of Computational Biology, Milan 20131, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gori
authors.affiliation: Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain.
authors.forename: Oscar
authors.initials: O
authors.lastname: Conchillo-Solé
authors.affiliation: Center for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Darawan
authors.initials: D
authors.lastname: Rinchai
authors.affiliation: Center for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Ganjana
authors.initials: G
authors.lastname: Lertmemongkolchai
authors.affiliation: Consiglio Nazionale delle Ricerche, Institute for Chemistry of Molecular Recognition, Department of Computational Biology, Milan 20131, Italy.
authors.forename: Renato
authors.initials: R
authors.lastname: Longhi
authors.affiliation: Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Bellaterra 08193, Spain; Catalan Institution for Research and Advanced Studies, Barcelona 08010, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Daura
authors.affiliation: Consiglio Nazionale delle Ricerche, Institute for Chemistry of Molecular Recognition, Department of Computational Biology, Milan 20131, Italy. Electronic address: giorgio.colombo@icrm.cnr.it.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Colombo
authors.affiliation: Department of Biosciences, University of Milan, Milan 20133, Italy; Consiglio Nazionale delle Ricerche, Institute of Biophysics, University of Milan, Milan 20133, Italy. Electronic address: martino.bolognesi@unimi.it.
authors.forename: Martino
authors.initials: M
authors.lastname: Bolognesi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000737:chemistry; D000942:Antigens, Bacterial / Q000737:chemistry* / Q000276:immunology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000276:immunology; D016957:Burkholderia pseudomallei / Q000276:immunology*; D002352:Carrier Proteins / Q000737:chemistry* / Q000276:immunology; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D018604:Epitope Mapping; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000737:chemistry; D008074:Lipoproteins / Q000737:chemistry* / Q000276:immunology; D008554:Melioidosis / Q000097:blood / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry* / Q000276:immunology; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D007106:Immune Sera; D008074:Lipoproteins; D010446:Peptide Fragments; C046506:oligopeptide-binding protein, bacteria