A comparison of the different helices adopted by α- and β-peptides suggests different reasons for their stability.
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.
Allison
Jane R
JR
Laboratory of Physical Chemistry, Swiss Federal Institute of Technology ETH, 8093 Zürich, Switzerland.
Müller
Marlen
M
van Gunsteren
Wilfred F
WF
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
D010455:Peptides; D014867:Water; D000432:Methanol