"Structural Instability of the Prion Protein upon M205S/R Mutations Revealed by Molecular Dynamics Simulations"Thomas Hirschberger, Martina Stork, Bernhard Schropp, Konstanze F. Winklhofer, Jörg Tatzelt, and Paul Tavan
Biophys. J. 90, 3908-3918 (2006).
The point mutations M205S and M205R have been demonstrated to severely disturb the folding and maturation process of the cellular prion protein PrP-C . These disturbances have been interpreted as consequences of mutation-induced structural changes in PrP, which were suggested to involve helix 1 and its attachment to helix 3, because the mutated residue M205 of helix 3 is located at the interface of these two helices. Furthermore, current models of the prion protein scrapie PrP-Sc, which is the pathogenic isoform of PrP-C in prion diseases, imply that helix 1 disappears during refolding of PrP-C into PrP-Sc . Based on molecular dynamics simulations of wild type and mutant PrP-C in aqueous solution here we show that the native PrP-C structure becomes strongly distorted within a few nanoseconds, once the point mutations M205S and M205R have been applied. In the case of M205R, this distortion is characterized by a motion of helix 1 away from the hydrophobic core into the aqueous environment and a subsequent structural decay. Together with experimental evidence on model peptides this decay suggests that the hydrophobic attachment of helix 1 to helix 3 at M205 is required for its correct folding into its stable native structure.
BMO authors (in alphabetic order):
Structural Stability of the Cellular Prion Protein PrPC studied by MD-Simulations
Computation of structure, electrostatics, and conformational dynamics of PrPC induced by binding of Cu(II)