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Updated: Jul 20, 2026

In vivo 19F MRI for Cell Tracking
Published on: November 25, 2013
Long-range 1H-19F distance measurement in peptides by solid-state NMR
Sungsool Wi1, Neeraj Sinha, Mei Hong
1Department of Chemistry, Iowa State University, Gilman 0108, Ames, IA 50011, USA.
A new nuclear magnetic resonance (NMR) method accurately measures long-range proton-fluorine (1H-19F) distances in solids up to 8 angstroms. This technique refines molecular structures, particularly useful for protein structural studies.
Area of Science:
- Solid-state Nuclear Magnetic Resonance (NMR) Spectroscopy
- Structural Biology
- Biophysics
Background:
- Determining long-range distances in solid samples is crucial for structural elucidation.
- Proton-fluorine (1H-19F) interactions offer unique insights but are challenging to measure in solids.
Purpose of the Study:
- To demonstrate a novel NMR technique for precise measurement of long-range 1H-19F distances in solid-state samples.
- To validate the technique's accuracy and utility in refining molecular conformations.
Main Methods:
- Development and application of a modified rotational-echo double resonance (REDOR) sequence.
- Incorporation of 1H homonuclear decoupling and composite 19F pulses to mitigate dephasing effects.
- Measurement of 1H-19F distances in the peptide f-MLF-OH.
Main Results:
- The modified REDOR technique successfully determined 1H-19F distances up to approximately 8 angstroms.
- A specific 1H-19F distance of 7.7 angstroms was measured in the peptide f-MLF-OH.
- The measured distance allowed for refinement of the phenylalanine (Phe) side chain conformation.
Conclusions:
- The demonstrated 1H-19F REDOR technique provides a robust method for measuring long-range distances in solids.
- This technique is valuable for enhancing the accuracy of three-dimensional structural models, especially for proteins.
- The method offers a significant advancement for structural biology applications requiring precise distance restraints.
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