Novel single chain antibodies to the prion protein identified by phage display

Virology. 2007 Feb 5;358(1):166-77. doi: 10.1016/j.virol.2006.08.023. Epub 2006 Sep 25.

Abstract

A well defined structure is available for the carboxyl half of the cellular prion protein (PrP(c)), while the structure of the amino terminal half of the molecule remains ill defined. The unstructured nature of the polypeptide has meant that relatively few of the many antibodies generated against PrP(c) recognise this region. To circumvent this problem, we have used a previously characterised and well expressed fragment derived from the amino terminus of PrP(c) as bait for panning a single chain antibody phage (scFv-P) library. Using this approach, we identified and characterised 1 predominant and 3 additional scFv-Ps that contained different V(H) and V(L) sequences and that bound specifically to the PrP(c) target. Epitope mapping revealed that all scFv-Ps recognised linear epitopes between PrP(c) residues 76 and 156. When compared with existing monoclonal antibodies (MAb), the binding of the scFvs was significantly different in that high level binding was evident on truncated forms of PrP(c) that reacted poorly or not at all with several pre-existing MAbs. These data suggest that the isolated scFv-Ps bind to novel epitopes within the amino-central region of PrP(c). In addition, the binding of MAbs to known linear epitopes within PrP(c) depends strongly on the endpoints of the target PrP(c) fragment used.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antibodies / immunology*
  • Antibodies / isolation & purification*
  • Antibodies, Monoclonal / immunology
  • Antibody Affinity
  • Antibody Specificity
  • Binding Sites, Antibody
  • Enzyme-Linked Immunosorbent Assay
  • Epitope Mapping
  • Immunoglobulin Fragments / immunology*
  • Immunoglobulin Fragments / isolation & purification*
  • Immunoglobulin Variable Region
  • Peptide Library*
  • PrPC Proteins / chemistry
  • PrPC Proteins / immunology*
  • Protein Structure, Tertiary
  • Sequence Alignment

Substances

  • Antibodies
  • Antibodies, Monoclonal
  • Immunoglobulin Fragments
  • Immunoglobulin Variable Region
  • Peptide Library
  • PrPC Proteins
  • immunoglobulin Fv