Peptide Side-COOH Groups Have Two Distinct Conformations under Biorelevant Conditions
| Autor: | Alberto Pérez de Alba Ortíz, Oleksandr O. Sofronov, Huib J. Bakker, Giulia Giubertoni, Bernd Ensing |
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| Přispěvatelé: | Molecular Simulations (HIMS, FNWI), Molecular Spectroscopy (HIMS, FNWI) |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Models
Molecular Letter Spectrophotometry Infrared Stereochemistry Molecular Conformation Peptide 010402 general chemistry 01 natural sciences chemistry.chemical_compound Isomerism Amide Proton transport 0103 physical sciences Aspartic acid Side chain General Materials Science Physical and Theoretical Chemistry Conformational isomerism chemistry.chemical_classification Aqueous solution 010304 chemical physics Amides 0104 chemical sciences Amino acid chemistry Peptides |
| Zdroj: | The Journal of Physical Chemistry Letters Journal of Physical Chemistry Letters, 11(9), 3466-3472. American Chemical Society |
| ISSN: | 1948-7185 |
| Popis: | The carboxyl (COOH) side chain groups of amino acids, such as aspartic acid, play an important role in biochemical processes, including enzymatic proton transport. In many theoretical studies, it was found that the (bio)chemical reactivity of the carboxyl group strongly depends on the conformation of this group. Interestingly, up to now there has been no experimental investigation of the geometry and the stability of different COOH conformers under biorelevant conditions. Here, we investigate the conformational isomerism of the side chain COOH group of N-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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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