title: A comparison of the different helices adopted by α- and β-peptides suggests different reasons for their stability.
abstract: The right-handed α-helix is the dominant helical fold of α-peptides, whereas the left-handed 3(14)-helix is the dominant helical fold of β-peptides. Using molecular dynamics simulations, the properties of α-helical α-peptides and 3(14)-helical β-peptides with different C-terminal protonation states and in the solvents water and methanol are compared. The observed energetic and entropic differences can be traced to differences in the polarity of the solvent-accessible surface area and, in particular, the solute dipole moments, suggesting different reasons for their stability.
authors.affiliation: Laboratory of Physical Chemistry, Swiss Federal Institute of Technology ETH, 8093 Zürich, Switzerland.
authors.forename: Jane R
authors.initials: JR
authors.lastname: Allison
authors.forename: Marlen
authors.initials: M
authors.lastname: Müller
authors.forename: Wilfred F
authors.initials: WF
authors.lastname: van Gunsteren
mesh_terms: D006860:Hydrogen Bonding; D000432:Methanol; D056004:Molecular Dynamics Simulation; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000737:chemistry*; D055550:Protein Stability; D017433:Protein Structure, Secondary; D013816:Thermodynamics; D014867:Water
chemical_list: D010455:Peptides; D014867:Water; D000432:Methanol