On the calculation of 3Jαβ-coupling constants for side chains in proteins
Abstract Structural knowledge about proteins is mainly derived from values of observables, measurable in NMR spectroscopic or X-ray diffraction experiments, i.e. absorbed or scattered intensities, through theoretically derived relationships between structural quantities such as atom positions or torsional angles on the one hand and observable quantities such as squared structure factor amplitudes, NOE intensities or 3
J-coupling constants on the other. The standardly used relation connecting 3
J-couplings to torsional angles is the Karplus relation, which is used in protein structure refinement as well as in the evaluation of simulated properties of proteins. The accuracy of the simple and generalised Karplus relations is investigated using side-chain structural and 3
J αβ-coupling data for three different proteins, Plastocyanin, Lysozyme, and FKBP, for which such data are available. The results show that the widely used Karplus relations are only a rough estimate for the relation between 3
J αβ-couplings and the corresponding Ï?1-angle in proteins.
- Content Type Journal Article
- Category Article
- Pages 1-24
- DOI 10.1007/s10858-012-9634-5
- Authors
- Denise Steiner, Laboratory of Physical Chemistry, ETH, Swiss Federal Institute of Technology, 8093 Zurich, Switzerland
- Jane R. Allison, Laboratory of Physical Chemistry, ETH, Swiss Federal Institute of Technology, 8093 Zurich, Switzerland
- Andreas P. Eichenberger, Laboratory of Physical Chemistry, ETH, Swiss Federal Institute of Technology, 8093 Zurich, Switzerland
- Wilfred F. van Gunsteren, Laboratory of Physical Chemistry, ETH, Swiss Federal Institute of Technology, 8093 Zurich, Switzerland
Source: Journal of Biomolecular NMR