Related Experiment Video
Updated: Apr 25, 2026

High-Pressure NMR Experiments for Detecting Protein Low-Lying Conformational States
Published on: June 29, 2021
Pressure response of amide one-bond J-couplings in model peptides and proteins
Joerg Koehler1, Markus Beck Erlach, Edson Crusca
1Centre of Magnetic Resonance in Chemistry and Biomedicine (CMRCB), Institute of Biophysics and Physical Biochemistry, University of Regensburg, Universitätsstraße 31, 93047, Regensburg, Germany.
Abstract:
The pressure dependence of the one-bond indirect spin-spin coupling constants (1)J(N-H) was studied in the protected tetrapeptides Ac-Gly-Gly-Xxx-Ala-NH2 (with Xxx being one of the 20 proteinogenic amino acids). The response of the (1)J(N-H) coupling constants is amino acid type specific, with an average increase of its magnitude by 0.6 Hz at 200 MPa. The variance of the pressure response is rather large, the largest pressure effect is observed for asparagine where the coupling constant becomes more negative by -2.9 Hz at 200 MPa. The size of the J-coupling constant at high pressure is positively correlated with its low pressure value and the β-propensity, and negatively correlated with the amide proton shift and the first order nitrogen pressure coefficient and the electrostatic solvation free energy.
Related Concept Videos
Peptide Bonds
Spin–Spin Coupling: One-Bond Coupling
¹H NMR: Long-Range Coupling
In alkenes, spin information is communicated via σ–π overlap, as seen in allylic (four-bond) and homoallylic (five-bond) couplings. These coupling interactions are stronger when the σ bond is parallel to the alkene...
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
NMR Spectroscopy Of Amines
Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...

