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Updated: Jan 16, 2026
10:54
Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
Published on: February 23, 2016
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Dissolution Dynamic Nuclear Polarization of the 77Se Nucleus.
Eul Hyun Suh1, James Ratnakar1, Jaspal Singh1
1Advanced Imaging Research Center, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390.
Analysis & Sensing
|October 6, 2025
Summary
Dissolving dynamic nuclear polarization (DNP) NMR can enhance signals for selenium-77 (77Se) in liquid states without enrichment. Signal enhancement depends heavily on the selenium compound's molecular symmetry, with some showing significant boosts.
Area of Science:
- Nuclear Magnetic Resonance (NMR) Spectroscopy
- Selenium Chemistry
- Biophysical Chemistry
Background:
- Selenium-77 (77Se) NMR is valuable for characterizing selenium-containing molecules, including proteins.
- Detecting 77Se in biological samples is difficult due to its low sensitivity and natural abundance (7.6%).
- Enrichment is typically required for effective 77Se detection, posing a challenge for biological studies.
Purpose of the Study:
- To investigate the feasibility of enhancing 77Se NMR signals in the liquid state using dissolution dynamic nuclear polarization (DNP) NMR.
- To determine if DNP can circumvent the need for isotopic enrichment of 77Se in biological samples.
- To assess the impact of molecular symmetry on 77Se signal enhancement via DNP.
Main Methods:
- Dissolution dynamic nuclear polarization (DNP) NMR experiments were conducted on three selenium compounds: sodium selenate, sodium selenite, and selenocystine.
- These compounds were chosen for their varying molecular symmetries.
- Experiments utilized commercially available DNP NMR hardware at a field strength of 9.4 T.
Main Results:
- Dissolution DNP NMR successfully enhanced 77Se signals, demonstrating its feasibility.
- Significant signal enhancements were observed: 1368-fold for selenate and 125-fold for selenite.
- No significant enhancement was achieved for selenocystine, highlighting the strong dependence on molecular symmetry.
- The dominant spin-lattice relaxation mechanism for 77Se, chemical shift anisotropy, is influenced by molecular symmetry.
Conclusions:
- 77Se NMR signal enhancement using dissolution DNP is achievable with standard equipment.
- The degree of signal enhancement is critically dependent on the molecular symmetry of the selenium compound.
- This DNP approach offers a potential method to improve 77Se detection in biological systems without isotopic enrichment.
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