n →π* Interactions of Amides and Thioamides: Implications for Protein Stability
Year: 2013
Type: article
Abstract: Carbonyl-carbonyl interactions between adjacent backbone amides have been implicated in the conformational stability of proteins. By combining experimental and computational approaches, we show that relevant amidic carbonyl groups associate through an n→π* donor-acceptor interaction with an energy of at least 0.27 kcal/mol. The n→π* interaction between two thioamides is 3-fold stronger than between two oxoamides due to increased overlap and reduced energy difference between the donor and acceptor orbitals. This result suggests that backbone thioamide incorporation could stabilize protein structures. Finally, we demonstrate that intimate carbonyl interactions are described more completely as donor-acceptor orbital interactions rather than dipole-dipole interactions.
DOI: 10.1021/ja4033583
Institution: University of Wisconsin–Madison
Language: English
Subfield: Physical and Theoretical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: Upgrade of cyber-enabled facility for computational chemistry research and education, Biotechnology Training Program, International Collaboration in Chemistry: Electron Delocalization in Polypeptide Structure and Stability, G6143541767, Chemistry and Biology of Collagen, G709003904, G7488701177, G9000064814
OpenAlex ID: W1969697060