A molecular dynamics study on the conformational stability of PrP 180–193 helix II prion fragment

Molecular dynamics of PrP 180–193 has allowed us to investigate the stability of the α-helical conformation of the zwitterionic peptide (L1) and the neutralized (L2). In water, the helical structure of L1 is unstable; in L2, the α-helix breaks up in the middle at Gln186, and the two resulting connected helices are stable. The hydrophobic enviroment decreases the stability of the helical structure of L1, this effect is more evident for L2 for which the unfolding of the C-terminus is followed by the formation of an intramolecular hydrogen bond connecting His187 with Thr191.