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Title: A comparison of the structure of the PK-sensitive and PK-resistant forms of PrPSc(Abstract)

item Silva, Christopher - Chris
item SAJNANI, GUSTAVO - University Of Santiago De Compostela
item RAMOS, ADRIANA - University Of Santiago De Compostela
item PASTRANA, MIGUEL - University Of Santiago De Compostela
item Onisko, Bruce
item Erickson-Beltran, Melissa
item Antaki, Elizabeth
item Dynin, Irina
item VAZQUEZ-FERNANDEZ, ESTER - University Of Santiago De Compostela
item SIGURDSON, CHRISTINA - University Of California
item Carter, John
item REQUENA, JESUS - University Of Santiago De Compostela

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2013
Publication Date: 5/24/2013
Citation: Silva, C.J., Sajnani, G., Ramos, A., Pastrana, M.A., Onisko, B.C., Erickson-Beltran, M.L., Antaki, E.M., Dynin, I.A., Vazquez-Fernandez, E., Sigurdson, C.J., Carter, J.M., Requena, J.R. 2013. A comparison of the structure of the PK-sensitive and PK-resistant forms of PrPSc(Abstract). Meeting Abstract. PS 26.

Interpretive Summary:

Technical Abstract: Background/Introduction. One of the distinctive phenotypes of the infectious isoform of PrP(PrPSc)is its resistance to proteinase K (PK) digestion. The diagnosis of prion diseases is based on this phenotypic observation. More recently, researchers determined that there is a sizeable fraction of PrPSc that is sensitive to PK hydrolysis(sPrPSc). We wished to determine if there was a phenotypic or biochemical difference between PrPSc and the sub-fractions of PK-resistant PrPSc (rPrPSc) and sPrPSc. Materials and Methods. We used our previously reported method of isolating PrPSc, sPrPSc and rPrPSc. These three fractions were bioassayed to compare their relative infectivity using the 263K strain of hamster-adapted scrapie. In addition we performed an immunohistochemical analysis of the three forms to determine whether they displayed the same pathology. The structural characteristics of the three forms were analyzed by mass spectrometry (MS) of the partial PK digest of these fractions. In addition we used partial PK digestion/MS to analyze the structures, sPrPSc and rPrPSc, of the drowsy (Dy) strain of hamster-adapted scrapie. Results and Conclusions. The sPrPSc and rPrPSc fractions from the 263K strain have comparable degrees of infectivity and although they contain different sized multimers, these multimers share similar structural properties Histopathological and immunohistochemical analyses of brains from animals inoculated (ic) with these fractions all showed an identical pathology. Furthermore, the PK-sensitive fractions of two hamster strains, 263K and Dy, showed strain-dependent differences in the ratios of the sPrPSc to the rPrPSc forms of PrPSc. Thus, although the sPrPSc and rPrPSc fractions have different resistance to PK-digestion, have previously been shown to sediment differently, and have a different distribution of multimers, they share a common structure and phenotype.