This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. High-field ESR spectra offer considerable improvements in orientational resolution over low field spectra, in many cases. Recognizing this, we have now successfully extended our capabilities to single-crystal rotation studies of Kramers and non-Kramers transition metal ions at high fields. Our design was influenced by single and multi-axis goniometers at W-band. However, we have incorporated a number of features into our design, which are specifically tailored to facilitate operation at low temperatures in a Fabry-P rot resonator. Multifrequency studies of single-crystal rotations allow one to more precisely determine the orientation-dependent terms in the spin-hamiltonian, such as the g-matrix, hyperfine-matrix and the zero-field splitting (ZFS) tensor. At sufficiently high fields, high-field spectra of single crystals with their narrower intrinsic linewidth compared to powder spectra may be used to assign the diagonal ZFS terms with confidence. At lower fields, the off-diagonal terms in the ZFS tensor become significant. This information, along with careful modeling of the ESR active moiety, can be used to obtain important structural information. Single-crystal studies of metalloenzymes with large ZFS splittings will particularly benefit from a multifrequency approach. Given the low or imperfect symmetry of many important biological systems, it is important to develop a goniometer that will work smoothly in a multi-frequency spectrometer with a multi-axis capability, as well as have efficient operation at low-temperatures for systems with short relaxation times. An improved version of the single-axis goniometer we have been using hitherto, featuring higher precision, is nearly completed and will serve as a test bed for developing a high precision multi-axis goniometer. We will incorporate this higher precision goniometer into our newly developed broadband bridge with improved temperature control and higher sensitivity to facilitate the study of a variety of biologically relevant single crystals.

National Institute of Health (NIH)
National Center for Research Resources (NCRR)
Biotechnology Resource Grants (P41)
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Cornell University
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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
Smith, Andrew K; Freed, Jack H (2012) Dynamics and ordering of lipid spin-labels along the coexistence curve of two membrane phases: an ESR study. Chem Phys Lipids 165:348-61
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
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
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

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