Structural intermediates in the putative pathway from the cellular prion protein to the pathogenic form.

摘要: The conversion of the alpha-helical, protease sensitive and noninfectious form prion protein (PrP(C)) into an insoluble, resistant, predominantly beta-sheeted infectious (PrP(Sc)) is fundamental event in formation. In present work, two soluble stable intermediate structural states are newly identified for recombinant Syrian hamster PrP(90-231) (recPrP), a dimeric alpha-helical state tetra- or oligomeric, beta-sheet rich state. 0.2% SDS at room temperature, recPrP exhibits random coil secondary structure as determined by circular dichroism. Reduction concentration to 0.06% leads first small increase content, whereas further dilution 0.02% results aquisition structure. reversible transition curve sigmoidal within narrow range concentrations (0.04 0.02%). Size exclusion chromatography chemical crosslinking revealed that dimeric, while oligomeric. Both intermediates stable. Thus, they should be accessible mechanistic studies. At 0.01% SDS, oligomeric aggregated large, insoluble structures observed fluorescence correlation spectroscopy. Our discussed with respect mechanism PrP(Sc) formation propagation prions.