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Updated: Jun 7, 2026
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Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
Published on: February 23, 2016
Spin-labeled heparins as polarizing agents for dynamic nuclear polarization
Björn C Dollmann1, Andrei L Kleschyov, Vasily Sen
1Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Summary
Spin-labeled heparins enhance nuclear magnetic resonance (NMR) signals using dynamic nuclear polarization (DNP). This method effectively boosts signals even with limited sample amounts, showing potential for biomacromolecule analysis.
Area of Science:
- Biophysical Chemistry
- Magnetic Resonance Spectroscopy
- Macromolecular Science
Background:
- Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful tool for molecular structure determination.
- Enhancing NMR signal sensitivity is crucial for analyzing low-concentration or small-sample biomolecules.
- Dynamic Nuclear Polarization (DNP) is a technique used to enhance NMR signal intensity.
Purpose of the Study:
- To introduce spin-labeled (SL) heparins as potentially biocompatible NMR signal enhancers.
- To investigate the use of SL-heparins for signal enhancement via Overhauser-type DNP.
- To determine and discuss the parameters governing DNP in SL-heparins.
Main Methods:
- Synthesis and characterization of spin-labeled heparin molecules.
- Application of Overhauser-type dynamic nuclear polarization (DNP) for NMR signal enhancement.
- Measurement and analysis of DNP enhancement factors and contributing relaxation mechanisms.
Main Results:
- SL-heparins demonstrated high (1)H DNP enhancement factors, reaching up to E=-110.
- Effective saturation of multiple hyperfine lines was observed, even with limited polarizing agents.
- Off-resonant electron paramagnetic resonance (EPR) hyperfine lines significantly contributed to saturation, independent of Heisenberg spin exchange (HSE) and T(1ne) relaxation.
Conclusions:
- Spin-labeled heparins are effective and potentially biocompatible agents for NMR signal enhancement.
- The study validates the use of Overhauser-type DNP for achieving substantial signal gains.
- Heterogeneous distribution of radicals on biomacromolecules can optimize DNP for samples with limited availability.
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