Dynamics of Nucleic Acids at Room Temperature Revealed by Pulsed EPR Spectroscopy |
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Authors: | Markus Gränz Nicole Erlenbach Dr Philipp Spindler Dr Dnyaneshwar B Gophane Dr Lukas S Stelzl Prof?Dr Snorri Th Sigurdsson Prof?Dr Thomas F Prisner |
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Institution: | 1. Institute of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic Resonance, Goethe University Frankfurt, Frankfurt am Main, Germany;2. Department of Chemistry, Science Institute, University of Iceland, Reykjavík, Iceland;3. Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany |
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Abstract: | The investigation of the structure and conformational dynamics of biomolecules under physiological conditions is challenging for structural biology. Although pulsed electron paramagnetic resonance (like PELDOR) techniques provide long‐range distance and orientation information with high accuracy, such studies are usually performed at cryogenic temperatures. At room temperature (RT) PELDOR studies are seemingly impossible due to short electronic relaxation times and loss of dipolar interactions through rotational averaging. We incorporated the rigid nitroxide spin label Ç into a DNA duplex and immobilized the sample on a solid support to overcome this limitation. This enabled orientation‐selective PELDOR measurements at RT. A comparison with data recorded at 50 K revealed averaging of internal dynamics, which occur on the ns time range at RT. Thus, our approach adds a new method to study structural and dynamical processes at physiological temperature in the <10 μs time range with atomistic resolution. |
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Keywords: | conformational dynamics DEER spectroscopy DNA EPR spectroscopy PELDOR spectroscopy |
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