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14:44
Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Measuring amide nitrogen quadrupolar coupling by high-resolution 14N/13C NMR correlation under magic-angle spinning
1National High Magnetic Field Laboratory, 1800 East Paul Dirac Drive, Tallahassee, Florida 32310, USA. gan@magnet.fsu.edu
Journal of the American Chemical Society
|May 4, 2006
Summary
This study presents a new method for measuring amide nitrogen 14N quadrupolar coupling in polypeptides using a 2D 14N/13C correlation experiment. This technique offers a sensitive approach for probing molecular structure and dynamics in various molecules.
Area of Science:
- Nuclear Magnetic Resonance Spectroscopy
- Solid-State NMR
- Chemical Physics
Background:
- Nitrogen-14 (14N) quadrupolar coupling provides valuable information about molecular structure and dynamics.
- Traditional methods for measuring 14N quadrupolar coupling can be challenging due to spectral complexity and low sensitivity.
Purpose of the Study:
- To develop and present a novel two-dimensional (2D) 14N/13C correlation experiment for precise measurement of amide nitrogen 14N quadrupolar coupling.
- To demonstrate the applicability of this method for analyzing natural abundant polypeptides.
Main Methods:
- Utilized a heteronuclear multiple-quantum correlation (HMQC)-type pulse sequence for 2D 14N/13C correlation.
- Employed magic-angle spinning (MAS) to achieve high spectral resolution.
- Correlated directly bonded 14N/13C pairs through J and residual dipolar couplings.
- Determined 14N quadrupolar coupling from isotropic second-order quadrupolar shifts by comparing 14N and 15N peak positions.
Main Results:
- Successfully measured amide nitrogen 14N quadrupolar coupling in a natural abundant polypeptide.
- Achieved high spectral resolution and sensitivity by leveraging 13C detection.
- The method accurately quantifies the isotropic second-order quadrupolar shift.
Conclusions:
- The developed 2D 14N/13C correlation experiment is effective for measuring 14N quadrupolar coupling.
- This technique offers a sensitive and high-resolution approach applicable to diverse organic, inorganic, and biological molecules.
- 14N quadrupolar coupling can be reliably used as a probe for molecular structure and dynamics.
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