Solution-phase chemical shift anisotropy as a promising tool to probe intermolecular interactions and peptide bond geometry: a case study on 15N-labeled Nα-t-Boc-L-valine
✍ Scribed by Katalin E. Kövér; Gyula Batta; Victor J. Hruby
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 211 KB
- Volume
- 41
- Category
- Article
- ISSN
- 0749-1581
- DOI
- 10.1002/mrc.1258
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✦ Synopsis
Abstract
Geometry‐dependent chemical shift anisotropy (CSA~g~) values of ^1^H and ^15^N nuclei have been determined in solution for ^15^N‐labeled, N^α^‐t‐Boc‐L‐valine by measurements of CSA/dipole–dipole cross‐correlated relaxation rates using longitudinal variants of the recently proposed one‐dimensional cross‐correlation experiments. We demonstrate that solvent dependence of the CSA~g~ is an invaluable tool for monitoring intermolecular H‐bonding interactions. In addition, enhanced temperature dependence was observed for CSA~g~, which indicates that the anisotropy of chemical shift is more sensitive to subtle changes in the electronic environment of the nucleus than the motionally averaged isotropic chemical shift.
^15^N CSA~g~ values have been determined in cyclosporin A at natural isotope abundance using the proposed ^1^H‐detected pulse schemes. A remarkable correlation was observed between the measured ^15^N CSA~g~ and the peptide ω angle, taken from the X‐ray structure of cyclosporin A. Copyright © 2003 John Wiley & Sons, Ltd.