Prion protein (PrP) synthetic peptides induce cellular PrP to acquire properties of the scrapie isoform

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Date

1995-11

Authors

Kaneko, K.
Peretz, David
Pan, K. K.
Blochberger, Thomas C.
Wille, H.
Gabizon, R.
Griffith, O. H.
Cohen, F. E.
Baldwin, Michael A.
Prusiner, Stanley B.

Journal Title

Journal ISSN

Volume Title

Publisher

Proceedings of the National Academy of Sciences

Abstract

Conversion of the cellular isoform of prion protein (PrPc) into the scrapie isoform (PrPSc) involves an increase in the /3-sheet content, diminished solubility, and resistance to proteolytic digestion. Transgenetic studies argue that PrPc and PrPSc form a complex during PrPScformation; thus, synthetic PrP peptides, which mimic the conformational pluralism of PrP, were mixed with PrPc to determine whether its properties were altered. Peptides encompassing two a-helical domains of PrP when mixed with PrPc produced a complex that displayed many properties of PrPSc. The PrPcpeptide complex formed fibrous aggregates and up to 65% of complexed PrPc sedimented at 100,000 x g for 1 h, whereas PrPc alone did not. These complexes were resistant to pro teolytic digestion and displayed a high /3-sheet content. Un expectedly, the peptide in a /3-sheet conformation did not form the complex, whereas the random coil did. Addition of 2% Sarkosyl disrupted the complex and rendered PrPc sensitive to protease digestion. While the pathogenic AllTV mutation increased the efficacy of complex formation, anti-PrP mono clonal antibody prevented interaction between PrPc and pep tides. Our findings in concert with transgenetic investigations argue that PrPc interacts with PrPSc through a domain that contains the first two putative a-helices. Whether PrPc-peptide complexes possess prion infectivity as determined by bioassays remains to be established.

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5 pages

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Citation

Kaneko, K., Peretz, D., Pan, K.-K., Blochberger, T. C., Wille, H., Gabizon, R., Griffith, O. H., Cohen, F. E., Baldwin, M. A., and Prusiner, S. B. (1995) Prion protein (Pr) synthetic peptides induce cellular PrP to acquire properties of the scrapie isoform. Proc. Natl. Acad. Sci. USA, 92, 11160-11164.