Peptide Side-COOH Groups Have Two Distinct Conformations under Biorelevant Conditions
Oleksandr O. Sofronov, Giulia Giubertoni, Alberto Pérez de Alba Ortíz, Bernd Ensing, Huib J. Bakker
Abstract
-acetyl aspartic acid amide using polarization-resolved two-dimensional infrared spectroscopy. We find that the carboxyl group shows two distinct near-planar conformers (syn and anti) when dissolved in water at room temperature. Both conformers are significantly populated in aqueous solution (75 ± 10% and 25 ± 10% for syn and anti, respectively). Molecular dynamics simulations show that the anti conformer interacts more strongly with water molecules than the syn conformer, explaining why this conformer is significantly present in aqueous solution.
Topics & Concepts
Conformational isomerismChemistryAqueous solutionAmideSide chainMoleculeHydrogen bondStereochemistryAspartic acidInfrared spectroscopyAmino acidCrystallographyOrganic chemistryBiochemistryPolymerCrystallography and molecular interactionsProtein Structure and DynamicsMass Spectrometry Techniques and Applications