Rapid-Scan EPR of Immobilized Nitroxides

Authors

• Zhelin Yu, University of Denver
• Richard W. Quine, University of Denver
• George A. Rinard, University of Denver
• Mark Tseitlin, University of Denver
• Hanan Elajaili, University of Denver
• Velavan Kathirvelu, University of Denver
• Laura J. Clouston, University of Nebraska-Lincoln
• Przemysław J. Boratyński, University of Nebraska-Lincoln
• Andrzej Rajca, University of Nebraska - LincolnFollow
• Richard A. Stein, Vanderbilt UniversityFollow
• Hassane Mchaourab, Vanderbilt University
• Sandra S. Eaton, University of Denver
• Gareth R. Eaton, University of Denver

Document Type

Article

Date of this Version

2014

Citation

J Magn Reson. 2014 October ; 247: 67–71.

Comments

Copyright © 2014 Elsevier Inc.

Abstract

X-band electron paramagnetic resonance spectra of immobilized nitroxides were obtained by rapid scan at 293 K. Scan widths were 155 G with 13.4 kHz scan frequency for ¹⁴N-perdeuterated tempone and for T4 lysozyme doubly spin labeled with an iodoacetamide spirocyclohexyl nitroxide and 100 G with 20.9 kHz scan frequency for ¹⁵N-perdeuterated tempone. These wide scans were made possible by modifications to our rapid-scan driver, scan coils made of Litz wire, and the placement of highly conducting aluminum plates on the poles of a Bruker 10" magnet to reduce resistive losses in the magnet pole faces. For the same data acquisition time, the signal-to-noise for the rapid-scan absorption spectra was about an order of magnitude higher than for continuous wave first-derivative spectra recorded with modulation amplitudes that do not broaden the lineshapes.