Structural and dynamical studies of all-trans and all-cis cyclo[(1R,3S)-gamma-Acc-Gly]3 peptides

J Mol Model. 2008 Dec;14(12):1147-57. doi: 10.1007/s00894-008-0357-1. Epub 2008 Sep 16.

Abstract

The quantum chemical and molecular dynamics studies have been performed to infer the structural changes of all-trans and all-cis forms of cyclo[(1R,3S)-3-aminocyclohexanecarboxylicacid(gamma-Acc)-alpha-Glycine(Gly)](3) hexapeptide. The backbone conformations of the above peptide have been analyzed using the valence and peptide deformation angles applying B3LYP/6-311G** level of theory. The conformational preference of the backbone of all-trans and all-cis cyclo[(1R,3S)-gamma-Acc-Gly](3) hexapeptides is found to depend on the puckering of cyclohexane rings. The non-uniform distribution of water inside the cavity is observed, where sometimes water molecules formed a chain like conformation through hydrogen bond networks while traversing the pore of all-cis cyclo[(1R,3S)-gamma-Acc-Gly](3) peptide. Larger relaxation times of the order of a hundred to two hundred pico seconds for active site...water hydrogen bond interactions were noticed. The hydrophobic nature of the cavity of all-trans cyclo[(1R,3S)-gamma-Acc-Gly](3) due to the presence of cyclohexane moiety has been analyzed. Further this investigation emphasized on the non-transport of molecules through the pore of all-trans cyclo[(1R,3S)-gamma-Acc-Gly](3) peptide due to the obstruction produced by cyclohexane groups.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Catalytic Domain
  • Computer Simulation
  • Hydrogen Bonding
  • Hydrophobic and Hydrophilic Interactions
  • Isomerism
  • Models, Molecular
  • Oligopeptides / chemistry*
  • Peptides, Cyclic / chemistry*
  • Water / chemistry

Substances

  • Oligopeptides
  • Peptides, Cyclic
  • cyclo(3-aminocyclohexanecarboxylicacid-glycyl)3 hexapeptide
  • Water