Seeded conversion of recombinant prion protein to a disulfide-bonded oligomer by a reduction-oxidation process.
The infectious form of prion protein, PrP(Sc), self-propagates by its conversion of the normal, cellular prion protein molecule PrP(C) to another PrP(Sc) molecule. It has not yet been demonstrated that recombinant prion protein can convert prion protein molecules from PrP(C) to PrP(Sc). Here we show that recombinant hamster prion protein is converted to a second form, PrP(RDX), by a redox process in vitro and that this PrP(RDX) form seeds the conversion of other PrP(C) molecules to the PrP(RDX) form. The converted form shows properties of oligomerization and seeded conversion that are characteristic of PrP(Sc). We also find that the oligomerization can be reversed in vitro. X-ray fiber diffraction suggests an amyloid-like structure for the oligomerized prion protein. A domain-swapping model involving intermolecular disulfide bonds can account for the stability and coexistence of two molecular forms of prion protein and the capacity of the second form for self-propagation.
Lee
Sangho
S
Howard Hughes Medical Institute, Molecular Biology Institute, UCLA-DOE Institute for Genomics and Proteomics and Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1570, USA.
Eisenberg
David
D
D000818:Animals; D006224:Cricetinae; D004220:Disulfides; D004591:Electrophoresis, Polyacrylamide Gel; D019286:Endopeptidase K / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015151:Immunoblotting; D008854:Microscopy, Electron; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010957:Plasmids / Q000378:metabolism; D011328:Prions / Q000737:chemistry*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry*; D014961:X-Ray Diffraction
D004220:Disulfides; D011328:Prions; D011994:Recombinant Proteins; D019286:Endopeptidase K