biostudies-literatureImani ZAgence Nationale de la Recherche9191-9197https://www.ebi.ac.uk/biostudies/studies/S-EPMC8163419biostudies-literatureUnknown11(34)In addition to the classical N-H⋯O[double bond, length as m-dash]C non-covalent interaction, less conventional types of hydrogen bonding, such as N-H⋯S, may play a key role in determining the molecular structure. In this work, using theoretical calculations in combination with spectroscopic analysis in both gas phase and solution phase, we demonstrate that both these H-bonding modes exist simultaneously in low-energy conformers of capped derivatives of Attc, a thietane α-amino acid. 6-Membered ring inter-residue N-H⋯S interactions (C6^γ), assisted by hyperconjugation between the thietane ring and the backbone, combine with 5-membered ring intra-residue backbone N-H⋯O[double bond, length as m-dash]C interactions (C5) to provide a C5-C6^γ feature that stabilizes a planar Chemical scienceConformation control through concurrent N-H⋯S and N-H⋯O[double bond, length as m-dash]C hydrogen bonding and hyperconjugation effects.PMC8163419ANR-17-CE29-0008ANR-10-LABX-0039-PALMLe Barbu-Debus KMundlapati VRMons MRobin SImani ZGuillot RZehnacker AAitken DJBrenner VGoldsztejn GBaltaze JPGloaguen EfalseConformation control through concurrent N-H⋯S and N-H⋯O[double bond, length as m-dash]C hydrogen bonding and hyperconjugation effects.In addition to the classical N-H⋯O[double bond, length as m-dash]C non-covalent interaction, less conventional types of hydrogen bonding, such as N-H⋯S, may play a key role in determining the molecular structure. In this work, using theoretical calculations in combination with spectroscopic analysis in both gas phase and solution phase, we demonstrate that both these H-bonding modes exist simultaneously in low-energy conformers of capped derivatives of Attc, a thietane α-amino acid. 6-Membered ring inter-residue N-H⋯S interactions (C6^γ), assisted by hyperconjugation between the thietane ring and the backbone, combine with 5-membered ring intra-residue backbone N-H⋯O[double bond, length as m-dash]C interactions (C5) to provide a C5-C6^γ feature that stabilizes a planar 2020-01-01T00:00:00Z2020 Aug2025-04-19T09:08:23.074Z2022-02-10T14:44:48.775ZS-EPMC81634193412316710.1039/d0sc03339a