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RESEARCH PRODUCT

Spin‐Labeled Heparins as Polarizing Agents for Dynamic Nuclear Polarization

Laura M. SchreiberKerstin MünnemannVasily D. SenValery G. GolubevAndrei L. KleschyovHans Wolfgang SpiessBjörn C. DollmannDariush Hinderberger

subject

Magnetic Resonance SpectroscopyMolecular StructureHeparinChemistryElectron Spin Resonance SpectroscopySite-directed spin labelingNuclear Overhauser effectNuclear magnetic resonance spectroscopyElectronAtomic and Molecular Physics and Opticslaw.inventionNuclear magnetic resonancelawMoleculeSpin LabelsCondensed Matter::Strongly Correlated ElectronsPhysical and Theoretical ChemistryElectron paramagnetic resonanceHyperfine structureMacromolecule

description

A potentially biocompatible class of spin-labeled macromolecules, spin-labeled (SL) heparins, and their use as nuclear magnetic resonance (NMR) signal enhancers are introduced. The signal enhancement is achieved through Overhauser-type dynamic nuclear polarization (DNP). All presented SL-heparins show high 1 H DNP enhancement factors up to E=-110, which validates that effectively more than one hyperfine line can be saturated even for spin-labeled polarizing agents. The parameters for the Overhauser-type DNP are determined and discussed. A striking result is that for spin-labeled heparins, the off-resonant electron paramagnetic resonance (EPR) hyperfine lines contribute a non-negligible part to the total saturation, even in the absence of Heisenberg spin exchange (HSE) and electron spin-nuclear spin relaxation (T 1ne ). As a result, we conclude that one can optimize the use of, for example, biomacro-molecules for DNP, for which only small sample amounts are available, by using heterogeneously distributed radicals attached to the molecule.

yearjournalcountryeditionlanguage
2010-10-19ChemPhysChem
https://doi.org/10.1002/cphc.201000559