Spin Hamiltonian Parameters for Cu(II)−Prion Peptide Complexes from L-Band Electron Paramagnetic Resonance Spectroscopy

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Format of Original

10 p.

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American Chemical Society

Source Publication

Journal of the American Chemical Society

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Original Item ID

doi: 10.1021/ja106550u


Cu(II) is an essential element for life but is also associated with numerous and serious medical conditions, particularly neurodegeneration. Structural modeling of crystallization-resistant biological Cu(II) species relies on detailed spectroscopic analysis. Electron paramagnetic resonance (EPR) can, in principle, provide spin Hamiltonian parameters that contain information on the geometry and ligand atom complement of Cu(II). Unfortunately, EPR spectra of Cu(II) recorded at the traditional X-band frequency are complicated by (i) strains in the region of the spectrum corresponding to the g orientation and (ii) potentially very many overlapping transitions in the g region. The rapid progress of density functional theory computation as a means to correlate EPR and structure, and the increasing need to study Cu(II) associated with biomolecules in more biologically and biomedically relevant environments such as cells and tissue, have spurred the development of a technique for the extraction of a more complete set of spin Hamiltonian parameters that is relatively straightforward and widely applicable. EPR at L-band (1−2 GHz) provides much enhanced spectral resolution and straightforward analysis via computer simulation methods. Herein, the anisotropic spin Hamiltonian parameters and the nitrogen coordination numbers for two hitherto incompletely characterized Cu(II)-bound species of a prion peptide complex are determined by analysis of their L-band EPR spectra.


Accepted version. Journal of the American Chemical Society, Vol. 133, No. 6 (February 2011): 1814–1823. DOI. © 2011 American Chemical Society. Used with permission.

Brian Bennett was affiliated with Medical College of Wisconsin at the time of publication.