title: Folding of a helix is critically stabilized by polarization of backbone hydrogen bonds: study in explicit water.
abstract: Multiple single-trajectory molecular dynamics (MD) simulation at room temperature (300 K) in explicit water was carried out to study the folding dynamics of an α-helix (PDB 2I9M ) using a polarized charge scheme that includes electronic polarization of backbone hydrogen bonds. Starting from an extended conformation, the 17-residue peptide was successfully folded into the native structure (α-helix) between 80 and 130 ns with a root-mean-square deviation of ~1.0 Å. Analysis of the time-dependent trajectories revealed that helix formation of the peptide started at the terminals and progressed toward the center of the peptide. For comparison, MD trajectories generated under various versions of standard AMBER force fields failed to show any significant or stable helix formation in our simulation. Our result shows clear evidence that the electronic polarization of backbone hydrogen bonds energetically stabilizes the helix formation and is critical to the stable folding of the short helix structure.
authors.affiliation: State Key Laboratory of Precision Spectroscopy, Department of Physics, and Institute of Theoretical and Computational Science, East China Normal University, Shanghai 200062, China.
authors.forename: Li L
authors.initials: LL
authors.lastname: Duan
authors.forename: Ya
authors.initials: Y
authors.lastname: Gao
authors.forename: Ye
authors.initials: Y
authors.lastname: Mei
authors.forename: Qing G
authors.initials: QG
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Tang
authors.forename: John Z H
authors.initials: JZ
authors.lastname: Zhang
mesh_terms: D016000:Cluster Analysis; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D010455:Peptides / Q000737:chemistry*; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D010455:Peptides; D014867:Water