NR AQHI
AU Apetri,A.C.; Surewicz,K.; Surewicz,W.K.
TI The effect of disease-associated mutations on the folding pathway of human prion protein
QU The Journal of Biological Chemistry 2004 Apr 23; 279(17): 18008-14
IA http://www.jbc.org/cgi/content/full/279/17/18008
PT journal article
AB Propagation of transmissible spongiform encephalopathies is believed to involve the conversion of cellular prion protein, PrPc, into a misfolded oligomeric form, PrPsc. An important step toward understanding the mechanism of this conversion is to elucidate the folding pathway(s) of the prion protein. We reported recently (Apetri, A. C., and Surewicz, W. K. (2002) J. Biol. Chem. 277, 44589-44592) that the folding of wild-type prion protein can best be described by a three-state sequential model involving a partially folded intermediate. Here we have performed kinetic stopped-flow studies for a number of recombinant prion protein variants carrying mutations associated with familial forms of prion disease. Analysis of kinetic data clearly demonstrates the presence of partially structured intermediates on the refolding pathway of each PrP variant studied. In each case, the partially folded state is at least one order of magnitude more populated than the fully unfolded state. The present study also reveals that, for the majority of PrP variants tested, mutations linked to familial prion diseases result in a pronounced increase in the thermodynamic stability, and thus the population, of the folding intermediate. These data strongly suggest that partially structured intermediates of PrP may play a crucial role in prion protein conversion, serving as direct precursors of the pathogenic PrPsc isoform.
MH Circular Dichroism; Dose-Response Relationship, Drug; Humans; Kinetics; Models, Molecular; *Mutation; Plasmids/metabolism; PrPsc Proteins/chemistry; Prions/*chemistry/*genetics; Protein Folding; Protein Isoforms; Recombinant Proteins/chemistry; Research Support, U.S. Gov't, P.H.S.; Thermodynamics; Time Factors; Urea/pharmacology
AD Department of Physiology and Biophysics and Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, USA
SP englisch
PO USA