Mapping functional prion-prion protein interaction sites using prion protein based peptide-arrays

Protein-protein interactions are at the basis of most if not all biological processes in living cells. Therefore, adapting existing techniques or developing new techniques to study interactions between proteins are of importance in elucidating which amino acid sequences contribute to these interactions. Such new insights may in turn lead to improved understanding of the processes underlying disease and possibly provide the basis for new therapeutic approaches. Here we describe the novel use of an ovine prion protein-based peptide-array normally used for determining prion-specific antibody epitopes, with the prospect that this would yield information on interaction sites between its PrP moiety and the ovine prion protein derived linear peptides. This adapted application of the peptide-array shows, by incubating the mature part of ovine (ARQ) PrPC fused to maltose binding protein (MBP), binding with between the PrP moiety and the ovine prion derived peptides occurs and indicates that several specific self-interactions between individual PrP molecules can occur; hereby illustrating that this adapted application of a peptide-array is a viable method to further specify which distinct amino acid sequences are involved in protein-protein interaction.