| Autor: |
Migliore M; Normandy Univ., COBRA UMR 6014 & FR 3038, Université de Rouen, INSA Rouen, CNRS, 1 rue Tesnière, 76821 Mont St Aignan, Cedex, France. vincent.tognetti@univ-rouen.fr laure.guilhaudis@univ-rouen.fr., Bonvicini A; Normandy Univ., COBRA UMR 6014 & FR 3038, Université de Rouen, INSA Rouen, CNRS, 1 rue Tesnière, 76821 Mont St Aignan, Cedex, France. vincent.tognetti@univ-rouen.fr laure.guilhaudis@univ-rouen.fr., Tognetti V; Normandy Univ., COBRA UMR 6014 & FR 3038, Université de Rouen, INSA Rouen, CNRS, 1 rue Tesnière, 76821 Mont St Aignan, Cedex, France. vincent.tognetti@univ-rouen.fr laure.guilhaudis@univ-rouen.fr., Guilhaudis L; Normandy Univ., COBRA UMR 6014 & FR 3038, Université de Rouen, INSA Rouen, CNRS, 1 rue Tesnière, 76821 Mont St Aignan, Cedex, France. vincent.tognetti@univ-rouen.fr laure.guilhaudis@univ-rouen.fr., Baaden M; Laboratoire de Biochimie Théorique, CNRS, UPR9080, Univ. Paris Diderot, Sorbonne Paris Cité, PSL Research University, 13 rue Pierre et Marie Curie, 75005 Paris, France., Oulyadi H; Normandy Univ., COBRA UMR 6014 & FR 3038, Université de Rouen, INSA Rouen, CNRS, 1 rue Tesnière, 76821 Mont St Aignan, Cedex, France. vincent.tognetti@univ-rouen.fr laure.guilhaudis@univ-rouen.fr., Joubert L; Normandy Univ., COBRA UMR 6014 & FR 3038, Université de Rouen, INSA Rouen, CNRS, 1 rue Tesnière, 76821 Mont St Aignan, Cedex, France. vincent.tognetti@univ-rouen.fr laure.guilhaudis@univ-rouen.fr., Ségalas-Milazzo I; Normandy Univ., COBRA UMR 6014 & FR 3038, Université de Rouen, INSA Rouen, CNRS, 1 rue Tesnière, 76821 Mont St Aignan, Cedex, France. vincent.tognetti@univ-rouen.fr laure.guilhaudis@univ-rouen.fr. |
| Abstrakt: |
Electronic circular dichroism is one of the most used spectroscopic techniques for peptide and protein structural characterization. However, while valuable experimental spectra exist for α-helix, β-sheet and random coil secondary structures, previous studies showed important discrepancies for β-turns, limiting their use as a reference for structural studies. In this paper, we simulated circular dichroism spectra for the best-characterized β-turns in peptides, namely types I, II, I' and II'. In particular, by combining classical molecular dynamics simulations and state-of-the-art quantum time-dependent density functional theory (with the polarizable embedding multiscale model) computations, two common electronic circular dichroism patterns were found for couples of β-turn types (namely, type I/type II' and type II/type I'), at first for a minimal di-peptide model (Ace-Ala-Ala-NHMe), but also for all sequences tested with non-aromatic residues in the central positions. On the other hand, as expected, aromatic substitution causes important perturbations to the previously found ECD patterns. Finally, by applying suitable approximations, these patterns were subsequently rationalized based on the exciton chirality rule. All these results provide useful predictions and pave the way for a possible experimental characterization of β-turns based on circular dichroism spectroscopy. |
