NR ASNX
AU Barducci,A.; Chelli,R.; Procacci,P.; Schettino,V.
TI Misfolding pathways of the prion protein probed by molecular dynamics simulations
QU Biophysical Journal 2005 Feb; 88(2): 1334-43
IA http://www.biophysj.org/cgi/content/full/88/2/1334
PT journal article
AB Although the cellular monomeric form of the benign prion protein is now well characterized, a model for the monomer of the misfolded conformation (PrPsc) remains elusive. PrPsc quickly aggregates into highly insoluble fibrils making experimental structural characterization very difficult. The tendency to aggregation of PrPsc in aqueous solution implies that the monomer fold must be hydrophobic. Here, by using molecular dynamics simulations, we have studied the cellular mouse prion protein and its D178N pathogenic mutant immersed in a hydrophobic environment (solution of CCl4), to reveal conformational changes and/or local structural weaknesses of the prion protein fold in unfavorable structural and thermodynamic conditions. Simulations in water have been also performed. Although observing in general a rather limited conformation activity in the nanosecond timescale, we have detected a significant weakening of the antiparallel beta-sheet of the D178N mutant in CCl4 and to a less extent in water. No weakening is observed for the native prion protein. The increase of beta-structure in the monomer, recently claimed as evidence for misfolding to PrPsc, has been also observed in this study irrespective of the thermodynamic or structural conditions, showing that this behavior is very likely an intrinsic characteristic of the prion protein fold.
MH Animals; Carbon Tetrachloride/chemistry; Comparative Study; Computer Simulation; Kinetics; Mice; *Models, Chemical; *Models, Molecular; Motion; PrPsc Proteins/analysis/*chemistry/*ultrastructure; Protein Conformation; Protein Denaturation; Protein Folding; Research Support, Non-U.S. Gov't; Structure-Activity Relationship; Water/chemistry
AD Dipartimento di Chimica, University of Florence, Sesto Fiorentino, Italy.
SP englisch
PO USA