Author/Editor | Kosmač, Miha; Koren, Simon; Giachin, Gabriele; Stoilova, Tatiana; Gennaro, Renato; Legname, Giuseppe; Čurin-Šerbec, Vladka | |
Title | Epitope mapping of a PrP(Sc)-specific monoclonal antibody: identification of a novel C-terminally truncated prion fragment | |
Type | članek | |
Source | Mol Immunol | |
Vol. and No. | Letnik 48, št. 5 | |
Publication year | 2011 | |
Volume | str. 746-50 | |
Language | eng | |
Abstract | Monoclonal antibodies (mAbs) against prion proteins (PrPs) are indispensable in research and diagnosis of prion diseases, however the majority of these bind both the cellular (PrPC) and the disease-associated (PrPSc) isoforms. According to the widely accepted protein-only hypothesis the two isoforms share the same sequence, but differ in their conformation. In the present study we set to determine the critical binding residues of our PrPSc-specific mAbs with the view of discerning which residues play a key role in the conformational transition between PrPC and PrPSc. Focussing on the V5B2 mAb that provided differential labelling of prion-affected tissue from individuals positive for transmissible spongiform encephalopathies, we performed alanine scanning and phage-display epitope mapping to elucidate the antigenic determinants of this mAb and gain insight into its specificity on a molecular level. We observed that instead of discriminating between the two prion protein isoforms based on conformational differences, V5B2 binds a previously uncharacterized C-terminally truncated form of PrPSc that ends with the residue Y226, which we named PrP226*. The addition of a single C-terminal amino-acid residue completely abolished V5B2 binding, while Western blots using recombinant full-length PrPs and PrPs terminating at Y226 confirmed that the V5B2 mAb discriminates between the two based on their difference in length. | |
Descriptors | PRIONS PRION DISEASES ANTIBODIES, MONOCLONAL EPITOPE MAPPING PRPSC PROTEINS RECOMBINANT PROTEINS ELECTROPHORESIS, POLYACRYLAMIDE GEL BLOTTING, WESTERN |