Entwicklung influenzabindender Peptide für die Biosensorik

The influenza virus infects mammals and birds. The first step of the infection cycle comprises the attachment of the viral surface protein hemagglutinin (HA) on glycan structures on epithelial cells within the respiratory tract of the host organism. Starting from the complementarity determining regions (CDRs) of the heavy chain of a monoclonal hemagglutinin-binding antibody three linear peptides were derived. The binding properties of these peptides was characterized experimentally using surface plasmon resonance spectroscopy. In accordance with accompanying molecular dynamics simulation it was shown, that two of the three peptides (PeB and PeC) were able to bind the influenza virus of the strain X31 (H3N2 A/Aichi/2/1968) comparably to the antibody itself. The interaction of peptide PeB, which was supposed to bind to the conserved receptor binding site at the HA, was then characterized more in detail. The detection of influenza viruses was achieved within the diagnostically relevant concentration range using defined immobilization conditions. The specificity of the peptide-virus-binding was proven by appropriate control experiments. Additionally, peptide PeB was able to inhibit the binding of X31 viruses to mimics of its natural receptor. Furthermore the structure-activity-relationship within all the amino acids of peptide PeB was characterized using a full substitutional analysis in a microarray format. This led to improved peptidic variants, which were able to bind different influenza serotypes and inhibit the influenza infection in vitro. The found peptides and their variants can now be used as receptor molecules in biosensors and also represent potential drug candidates.