Articles | Volume 6, issue 2
https://doi.org/10.5194/mr-6-257-2025
https://doi.org/10.5194/mr-6-257-2025
Research article
 | 
17 Nov 2025
Research article |  | 17 Nov 2025

γ effects identify preferentially populated rotamers of CH2F groups: side-chain conformations of fluorinated valine analogues in a protein

Elwy H. Abdelkader, Nicholas F. Chilton, Ansis Maleckis, and Gottfried Otting

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Cited articles

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Short summary
The small protein GB1, where all valine residues were replaced by fluorinated analogues containing one or two CH2F groups, produces 19F NMR (nuclear magnetic resonance) spectra with exceptional resolution. We establish a convenient strategy for their assignment and analyse the rotameric states of the CH2F groups by virtue of three-bond coupling constants and a γ effect on 13C chemical shifts, which is underpinned by DFT (density functional theory) calculations. Transient fluorine–fluorine contacts are documented by through-space 19F–19F couplings.
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