NR AJPH
AU Priola,S.A.; Chabry,J.; Chan,K.
TI Efficient conversion of normal prion protein (PrP) by abnormal hamster PrP is determined by homology at amino acid residue 155
QU Journal of Virology 2001 May; 75(10): 4673-80
PT journal article
AB In the transmissible spongiform encephalopathies, disease is closely associated with the conversion of the normal proteinase K-sensitive host prion protein (PrP-sen) to the abnormal proteinase K-resistant form (PrPres). Amino acid sequence homology between PrPres and PrP-sen is important in the formation of new PrPres and thus in the efficient transmission of infectivity across species barriers. It was previously shown that the generation of mouse PrPres was strongly influenced by homology between PrP-sen and PrPres at amino acid residue 138, a residue located in a region of loop structure common to PrP molecules from many different species. In order to determine if homology at residue 138 also affected the formation of PrPres in a different animal species, we assayed the ability of hamster PrPres to convert a panel of recombinant PrP-sen molecules to protease-resistant PrP in a cell-free conversion system. Homology at amino acid residue 138 was not critical for the formation of protease-resistant hamster PrP. Rather, homology between PrP-sen and hamster PrPres at amino acid residue 155 determined the efficiency of formation of a protease-resistant product induced by hamster PrPres. Structurally, residue 155 resides in a turn at the end of the first alpha helix in hamster PrP-sen; this feature is not present in mouse PrP-sen. Thus, our data suggest that PrPres molecules isolated from scrapie-infected brains of different animal species have different PrP-sen structural requirements for the efficient formation of protease-resistant PrP.
MH Amino Acids; Animal; Cell Line; Cell-Free System; Endopeptidase K/metabolism; Hamsters; Mice; Mutagenesis; Prions/genetics/*metabolism
AD Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA. spriola@nih.gov
SP englisch
PO USA