β-PrP form of human prion protein stimulates production of monoclonal antibodies to epitope 91–110 that recognise native PrPSc

Molecular Dynamics as an Approach to Study Prion Protein Misfolding and the Effect of Pathogenic Mutations

“…Further strands sometimes form in the remaining part that was included in the simulation. Antibody studies indicate that residues 90-120 undergo a conformational change upon conversion to PrP Sc [112][113][114] and a range of studies support the involvement of residues in this region in PrP Sc formation [108,110,111,115]. Our misfolding simulations also indicate the formation of an isolated strand in the loop preceding HA (res.…”

Characterization of Conformation-dependent Prion Protein Epitopes

“…Renaturation of Conformational PrP Epitopes-Our results shed light on previously reported difficulties surrounding antiPrP mAb epitope mapping, which resulted in speculation that PrP may be idiosyncratically processed by antigen-presenting cells (12), or to inferences that the epitopes of such mAbs are discontinuous, and/or that peptide fragments in this format are unable to adopt specific conformations required for antibody binding (12)(13)(14)(15)(16)(17). This latter hypothesis was rejected as highly unlikely (13), because all such antibodies bind PrP in Western blots, where PrP is defined by investigators as denatured (12, 13, 15, 18 -22).…”

“…Because this approach is laborious, ELISA-based peptide scanning has been the preferred method to map the approximate locations of epitopes. However, surprisingly few anti-PrP mAbs are amenable to this form of characterization, leading previous investigators to infer the existence of discontinuous PrP epitopes (12)(13)(14)(15)(16)(17). To date, the involvement of specific amino acid residues in such hypothesized conformational epitopes has not been described.…”

Conformational Properties of β-PrP

“…In contrast, amyloid fibrils generated from recombinant protein, and from other amyloidogenic proteins, do not elicit such a response. Together with recent data suggesting that prion disease is associated in vivo with dysfunction of the ubiquitinproteasome system (46), and the observation that antibodies raised against ␤-PrP are capable of recognizing native PrP Sc , but not PrP C (42)(43)(44), this suggests that ␤-PrP is likely to be of biological significance in prion disease. Here, we have established that the oligomeric species that make up the majority of ␤-PrP share a common ␤-sheet structure, suggesting that the arrangements of PrP chains within the oligomers is common throughout, and it is the macromolecular organization that is the predominant difference between the components of the oligomeric mixture.…”

“…Indeed, antibodies raised against ␤-PrP (e.g. ICSM33) are capable of recognizing native PrP Sc (but not PrP C ) (42)(43)(44). Subsequently, a related study examining the role of the disulfide bond in PrP folding confirmed that a monomeric molten globule-like form of PrP was formed on refolding the disulfide-reduced protein at acidic pH, but reported that, under their conditions, the circular dichroism response interpreted as ␤-sheet structure was associated with protein oligomerization (45).…”