title: Kinetics of antigen-antibody interactions employing a MALDI mass spectrometry immunoassay.
abstract: Time-course MALDI mass spectrometry immunoassays have been shown to be able to detect differences in the relative rates of binding of peptides, both from within and across epitopic domains, with antibodies in non-competitive and competitive experiments. A monoclonal antibody raised to target the HA1 subunit of the hemagglutinin antigen of type A H3N2 influenza strains is found to recognize two epitopic peptides comprising residues 109-125 and 158-166 that likely form part of an extended discontinuous domain. Time-course experiments show the smaller peptide binds antibody at a rate that is 5-fold faster than that for the larger peptide. A shorter segment of this larger peptide, comprised of residues 119-125, is also found to bind at twice the rate of the extended peptide. Studies of modified peptide variants and synthetic variants of HA peptide 119-125 has enabled important contact residues to be identified whose accessibilities in the native protein are in accord with the mass spectrometry results.
authors.affiliation: School of Molecular and Microbial Biosciences, The University of Sydney, Australia.
authors.forename: Bethny
authors.initials: B
authors.lastname: Morrissey
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Downard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000915:Antibody Affinity; D000937:Antigen-Antibody Reactions; D002417:Cattle; D000939:Epitopes / Q000276:immunology; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology; D007118:Immunoassay; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D007700:Kinetics; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D010455:Peptides