National Biomedical EPR Center

Octave bandwidth continuous wave microwave bridges designed and constructed at the EPR Center are available from 500 MHz to 1 GHz, 1–2 GHz, 2–4 GHZ, and 4–8 GHZ. Loop-gap resonators are available at discrete frequencies within these bandwidths.

Numerous microwave bridges are available at X-band, including Bruker, Varian, and EPR Center-built. An EPR Center-built bridge is available at 18 GHz and two bridges for use at Q-band, 35 GHz, are in place. One is an updated Varian and one is a Bruker. The Bruker bridge is configured for ENDOR. A third Q-band bridge with saturation recovery capability will be online in early 2015. In addition, Q-band DEER pulse EPR from Bruker is in daily operation.

A multi-arm W-band bridge is in regular use, with loop-gap resonator and saturation recovery capabilities. A D-band (140 GHz) bridge is nearing completion.

Strangeway RA, Hyde JS, Camenisch TG, Sidabras JW, Mett RR, Anderson JR, Ratke JR, Subczynski WK. (2017). Broadband W-band rapid frequency sweep considerations for Fourier transform EPR. Cell Biochem Biophys. 75(3-4):259-73. PMCID: PMC5693649

Sidabras JW, Strangeway RA, Mett RR, Anderson JR, Mainali L, Hyde JS. (2016). Hyperbolic-cosine waveguide tapers and oversize rectangular waveguide for reduced broadband insertion loss in W-band electron paramagnetic resonance spectroscopy. II. Broadband characterization. 87(3):034704. PMCID: PMC4798996

Mainali L, Sidabras JW, Camenisch TG, Ratke JJ, Raguz M, Hyde JS, Subczynski WK. (2014). Spin-label W-band EPR with seven-loop-six-gap resonator: application to lens membranes derived from eyes of a single donor. App Magn Reson. 45(12):1343-58. PMCID: PMC4273494

Mainali L, Hyde JS, Subczynski WK. (2013). Using spin-label W-band EPR to study membrane fluidity profiles in samples of small volume. J Magn Reson. 226:35-44. PMCID: PMC3529815

Subczynski WK, Mainali L, Camenisch TG, Froncisz W, Hyde JS. (2011). Spin-label oximetry at Q- and W-band. J Magn Reson. 209:142-148. PMCID: PMC3065517

Mett RR, Sidabras JW, Anderson JR, Hyde JS. (2011). Hyperbolic-cosine waveguide tapers and oversize rectangular waveguide for reduced broadband insertion loss in W-band electron paramagnetic resonance spectroscopy. Rev Sci Instrum. 82(7):074704. PMCID: PMC315584

Hyde JS, Strangeway RA, Camenisch TG, Ratke JJ, Froncisz W. (2010). W-band frequency-swept EPR. J Magn Reson. 205:93-101. PMCID: PMC2885579

Research Highlight #144 Hyperbolic-cosine waveguide tapers and oversize rectangular waveguide for reduced broadband insertion loss in W-band electron paramagnetic resonance spectroscopy (PDF)

Research Highlight #141 Spin-label saturation-recovery EPR at W-band: Applications for eye-lens lipid membranes (PDF)

Research Highlight #136 W-band frequency swept EPR (PDF)

Hyde JS, Bennet B, Kittell AW, Kowalski JM, Sidabris JW. (2013). Moving difference (MDIFF) non-adiabatic rapid sweep (NARS) EPR of copper (II). J Magn Reson. 236:15-25. PMCID: PMC3919454

Kittell AW, Hustedt EJ, Hyde JS. (2012). Inter-spin distance determination using L-band (1-2GHz) non-adiabatic rapid sweep electron paramagnetic resonance (NARS EPR). J Magn Reson. 221:51-6. PMCID: PMC3957363

Kittell AW, Camenisch TG, Ratke JJ, Sidabras JW, Hyde JS. Detection of undistorted continuous wave (CW) electron paramagnetic resonance (EPR) spectra with non-adiabatic rapid sweep (NARS) of the magnetic field. J Magn Reson. 211:228-233. PMCID: PMC3148028

Research Highlight #148 Long Range Inter-spin Distance Determination Under Near-Physiological Conditions Using L-band Non-Adiabatic Rapid Scan Electron Paramagnetic Resonance (NARS EPR) Spectroscopy (PDF)

Research Highlight #146 MDIFF NARS of Cu (II) in Frozen Solution (PDF)

Research Highlight #143 Measuring Inter-Spin Distances in the Borderline Region Using Very Low Frequency Non-Adiabatic Rapid Sweep Electron Paramagnetic Resonance (VLF NARS EPR) (PDF)

Research Highlight #142 NARS Spectroscopy in Square Planar Copper Complexes Having Nitrogen Ligands (PDF)

Mainali L, Feix JB, Hyde JS, Subczynski WK. (2011). Membrane fluidity profiles as deduced by saturation-recovery EPR measurements of spin-lattice relaxation times of spin labels. J Magn Reson. 212(2):418-25. PMCID: PMC3214655

Mainali L, Raguz M, Subczynski WK. (2011). Phase-separation and domain-formation in cholesterol-sphingomyelin mixture: pulse-EPR oxygen probing. Biophys J. 101(4):837-46. PMCID: PMC3175055

Hyde JS, Yin J-J, Subczynski WK, Camenisch TG, Ratke JJ, Froncisz W. (2004). Spin-label EPR T1 values using saturation recovery from 2 to 35 GHz. J Phys Chem B. 108(27):9524-9529.

Research Highlight #141 Spin-label saturation-recovery EPR at W-band: Applications for eye-lens lipid membranes (PDF)

The Bruker Q- and X-band E580 pulse spectrometer is capable of running DEER (double electron electron resonance), DQC (double quantum coherence), and ENDOR (electron nuclear double resonance) experiments at cryogenic temperatures. The primary use of this instrumentation is to quantitate distance measurements between paramagnetic probes on or within biomedically relevant proteins.

Zhuo Y, Vishnivetskiy SA, Zhan X, Gurevich VV, Klug CS. (2014). Identification of receptor binding-induced conformational changes in non-visual arrestins. J Biol Chem. 289:20991-21002. PMCID: PMC4110305

Dellisanti CD, Ghosh B, Hanson SM, Raspanti JM, Grant VA, Diarra GM, Schuh AM, Satyshur K, Klug CS, Czajkowski, C. (2013). Site-directed spin labeling reveals pentameric ligand-gated ion channel gating motions. PLoS Biol. 11(11): e1001714. PMCID: PMC3833874

Merten JA, Schultz KM, Klug CS. (2012). Concentration-dependent oligomerization and oligomeric arrangement of LptA. Protein Sci. 21:211-218. PMCID: PMC3324765

Schultz KM, Merten JA, Klug CS. (2011). Characterization of the E506Q and H537A dysfunctional mutants in the ABC transporter MsbA. Biochemistry. 50(18):3599-3608. PMCID: PMC3128438

Rice AJ, Alvarez FJD, Schultz KM, Klug CS, Davidson AL, Pinkett HW. (2013). EPR spectroscopy of MolB2C2-A reveals mechanism of transport for a bacterial type II molybdate importer. J Biol Chem. 288(29):21228-21235. PMCID: PMC3774390 *JBC Paper of the Week*

Sharma A, Gaidamakova EK, Matrosova VY, Bennett B, Daly MJ, Hoffman BM. (2013). Responses of Mn2+ speciation in Deinococcus radiodurans and Escherichia coli to gamma-radiation by advanced paramagnetic resonance methods. Proc Natl Acad Sci USA. 110(15):5945–5950. PMCID: PMC3625348

Anderson DM, Feix JB, Monroe AL, Peterson FC, Volkman BF, Haas AL, Frank DW. (2013). Identification of the major ubiquitin-binding domain of the Pseudomonas aeruginosa ExoU A2 phospholipase. J Biol Chem. 288:26741–26752. PMCID: PMC3772220