This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. A multifrequency approach combining high and low ESR frequencies can enable a decomposition of the complex dynamic modes affecting each site label on a protein labeled via site-directed spin-labeling (SDSL). In a recent study on T4 lysozyme using mutagens, to which a spin label is attached at different residues, we showed that the high-field/high-frequency-ESR (HFHF-ESR) experiments could be satisfactorily described by the microscopic order macroscopic disorder (MOMD) model in which only the internal dynamics is present. The slowly relaxing local structure (SRLS) model includes fitting parameters for the overall tumbling rates and internal modes. The MOMD model is a limiting case of SRLS model where the overall tumbling is too slow to affect the appearance of the spectrum. On the slower time scale of the 9GHz spectra both the faster internal modes and the slower overall tumbling are important. These studies have provided evidence for the potential of multifrequency ESR to map out the dynamic structure, on a site to site basis, of a macromolecule. The center has recently installed new HFHF-ESR cw spectrometers with superior signal to noise and temperature stability to previous versions, which will allow us to study the dynamic modes of the system with improved sensitivity and throughput capability over a range of frequencies from 9 to 240GHz. The availability of spectra for analysis over a range of frequencies, although a significant computational challenge, will provide detailed insights into the dynamic modes of the system. The implementation of continuously variable coupling to all of our resonators originally developed at 95GHz will be a crucial advance to further improve the sensitivity of our HFHF ESR spectrometers.

National Institute of Health (NIH)
National Center for Research Resources (NCRR)
Biotechnology Resource Grants (P41)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-BCMB-K (40))
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Cornell University
Schools of Arts and Sciences
United States
Zip Code
Jain, Rinku; Vanamee, Eva S; Dzikovski, Boris G et al. (2014) An iron-sulfur cluster in the polymerase domain of yeast DNA polymerase ?. J Mol Biol 426:301-8
Pratt, Ashley J; Shin, David S; Merz, Gregory E et al. (2014) Aggregation propensities of superoxide dismutase G93 hotspot mutants mirror ALS clinical phenotypes. Proc Natl Acad Sci U S A 111:E4568-76
Georgieva, Elka R; Borbat, Peter P; Ginter, Christopher et al. (2013) Conformational ensemble of the sodium-coupled aspartate transporter. Nat Struct Mol Biol 20:215-21
Airola, Michael V; Sukomon, Nattakan; Samanta, Dipanjan et al. (2013) HAMP domain conformers that propagate opposite signals in bacterial chemoreceptors. PLoS Biol 11:e1001479
Airola, Michael V; Huh, Doowon; Sukomon, Nattakan et al. (2013) Architecture of the soluble receptor Aer2 indicates an in-line mechanism for PAS and HAMP domain signaling. J Mol Biol 425:886-901
Sun, Yan; Zhang, Ziwei; Grigoryants, Vladimir M et al. (2012) The internal dynamics of mini c TAR DNA probed by electron paramagnetic resonance of nitroxide spin-labels at the lower stem, the loop, and the bulge. Biochemistry 51:8530-41
Yu, Renyuan Pony; Darmon, Jonathan M; Hoyt, Jordan M et al. (2012) High-Activity Iron Catalysts for the Hydrogenation of Hindered, Unfunctionalized Alkenes. ACS Catal 2:1760-1764
Dzikovski, Boris; Tipikin, Dmitriy; Freed, Jack (2012) Conformational distributions and hydrogen bonding in gel and frozen lipid bilayers: a high frequency spin-label ESR study. J Phys Chem B 116:6694-706
Gaffney, Betty J; Bradshaw, Miles D; Frausto, Stephen D et al. (2012) Locating a lipid at the portal to the lipoxygenase active site. Biophys J 103:2134-44
Maeda, Kiminori; Lodge, Matthew T J; Harmer, Jeffrey et al. (2012) Electron tunneling in lithium-ammonia solutions probed by frequency-dependent electron spin relaxation studies. J Am Chem Soc 134:9209-18

Showing the most recent 10 out of 72 publications