Self-assembled peptide amphiphiles function as multivalent binder with increased hemagglutinin affinity

BACKGROUND: A promising way in diagnostic and therapeutic applications is the development of peptide amphiphiles (PAs). Peptides with a palmitic acid alkylchain were designed and characterized to study the effect of the structure modifications on self-assembling capabilities and the multiple binding capacity to hemagglutinin (HA), the surface protein of influenza virus type A. The peptide amphiphiles consists of a hydrophilic headgroup with a biological functionality of the peptide sequence and a chemically conjugated hydrophobic tail. In solution they self-assemble easily to micelles with a hydrophobic core surrounded by a closely packed peptide-shell. RESULTS: In this study the effect of a multiple peptide binding partner to the receptor binding site of HA could be determined with surface plasmon resonance measurements. The applied modification of the peptides causes signal amplification in relationship to the unmodified peptide wherein the high constant specificity persists. The molecular assembly of the peptides was characterized by the determination of critical micelle concentration (CMC) with concentration of 10(-5) M and the colloidal size distribution. CONCLUSION: The modification of the physico-chemical parameters by producing peptide amphiphiles form monomeric structures which enhances the binding affinity and allows a better examination of the interaction with the virus surface protein hemagglutinin.