Early Events in the Folding of an Amphipathic Peptide A Multi- Nanosecond Molecular Dynamics Study (Paperback) (ISBN-13: 9781289291303)

Folding of the capped LQQLLQQLLQL peptide is investigated at the water-hexane interface by molecular dynamics simulations over 161.5 nanoseconds. Initially placed in the aqueous phase as a beta-strand, the peptide rapidly adsorbs to the interface, where it adopts an amphipathic conformation. The marginal presence of non-amphipathic structures throughout the complete trajectory indicate- that the corresponding conformations are strongly disfavored at the interface. It is further suggestive that folding in an interfacial environment proceeds through a pathway of successive amphipathic intermediates. The energetic and entropic penalties involved in the conformational changes along this pathway markedly increase the folding time-scales of LQQLLQQLLQL, explaining why the alpha-helix, the hypothesized lowest free energy structure for a sequence with a hydrophobic periodicity of 3.6, has not been reached yet. The formation of a type I beta-turn at the end of the simulation confirms the importance of such motifs as initiation sites allowing the peptide to coalesce towards a secondary structure.

Author: Nasa Technical Reports Server (Ntrs)
ISBN-10: 1289291306
ISBN-13: 9781289291303
Publisher: Bibliogov
Language: English
Published: 08/07/2013
Pages: 52
Format: Paperback
Weight: 0.24lbs
Size: 9.69h x 7.44w x 0.11d