Nanopore detection of antibody prion interactions

In nanopore analysis, peptides and proteins can be detected by the change in current when single molecules interact with an α-hemolysin pore embedded in a lipid membrane. A prion peptide, PrP(143–169), can readily translocate through the pore, but on the addition of monoclonal antibody M2188, which binds the peptide, the number of translocations is reduced because the complex is too large to translocate. At a peptide-to-immunoglobulin G (IgG) ratio of 2:1, only bumping events were observed. The event profile of a control peptide that does not bind the antibody was unchanged. Similarly, the presence of the antibody prevents translocation of the full-length prion protein. Because a nanopore can detect a single molecule, these experiments represent an important first step towards the development of a sensitive prion detector.