Abstract |
In the transmissible spongiform encephalopathies, normal prion protein ( PrP-sen) is converted to a protease-resistant isoform, PrP-res, by an apparent self-propagating activity of the latter. Here we describe new, more physiological cell-free systems for analyzing the initial binding and subsequent conversion reactions between PrP-sen and PrP-res. These systems allowed the use of antibodies to map the sites of interaction between PrP-sen and PrP-res. Binding of antibodies (alpha219-232) to hamster PrP-sen residues 219-232 inhibited the binding of PrP-sen to PrP-res and the subsequent generation of PK-resistant PrP. However, antibodies to several other parts of PrP-sen did not inhibit. The alpha219-232 epitope itself was not required for PrP-res binding; thus, inhibition by alpha219-232 was likely due to steric blocking of a binding site that is close to, but does not include the epitope in the folded PrP-sen structure. The selectivity of the binding reaction was tested by incubating PrP-res with cell lysates or culture supernatants. Only PrP-sen was observed to bind PrP-res. This highly selective binding to PrP-res and the localized nature of the binding site on PrP-sen support the idea that PrP-sen serves as a critical ligand and/or receptor for PrP-res in the course of PrP-res propagation and pathogenesis in vivo.
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Authors | M Horiuchi, B Caughey |
Journal | The EMBO journal
(EMBO J)
Vol. 18
Issue 12
Pg. 3193-203
(Jun 15 1999)
ISSN: 0261-4189 [Print] England |
PMID | 10369660
(Publication Type: Journal Article)
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Chemical References |
- Antibodies, Monoclonal
- Epitopes
- Immunoglobulin Fab Fragments
- PrPC Proteins
- PrPSc Proteins
- Protein Isoforms
- Sodium Chloride
- Potassium Chloride
- Carboxypeptidases
- Endopeptidases
- Endopeptidase K
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Topics |
- Animals
- Antibodies, Monoclonal
(pharmacology)
- Binding Sites
- Brain
- Carboxypeptidases
(metabolism)
- Cricetinae
- Endopeptidase K
(metabolism)
- Endopeptidases
(metabolism)
- Epitopes
(genetics, immunology)
- Glycosylation
- Immunoglobulin Fab Fragments
(pharmacology)
- Mice
- Models, Molecular
- Molecular Weight
- Potassium Chloride
(pharmacology)
- PrPC Proteins
(chemistry, genetics, immunology, metabolism)
- PrPSc Proteins
(chemistry, genetics, immunology, metabolism)
- Protein Binding
(drug effects)
- Protein Conformation
(drug effects)
- Protein Isoforms
(chemistry, genetics, immunology, metabolism)
- Sequence Deletion
- Sodium Chloride
(pharmacology)
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