The Freed Group develops unique methods of electron-spin resonance to study the structure, dynamics, and functional mechanisms of protein complexes, membrane proteins, and RNA-protein interactions. The research includes projects in experimental chemical physics and biophysics, theoretical chemistry, and instrumentation development.
* Application of magnetic resonance to problems in chemical physics and biophysics
* Molecular dynamics, reactivity, and structure in condensed media and in model membranes
* Development of ESR spectroscopy into a tool to analyze molecular dynamics
* Superstructures of protein complexes by ESR
A Multifrequency ESR Study of the Dynamics of Spin-Labeled T4 Lysozyme, Z. Zhang, M. Fleissner, D. Tipikin, Z. Liang, J.K. Moscicki, K.A. Earle, W. Hubbell, J.H. Freed, J. Phys. Chem. B, 114, 5503-5521 (2010).
The Lipid-Binding Domain of Wild Type and Mutant Alpha-Synuclein: Compactness and Interconversion Between the Broken-and Extended-Helix Forms, E.R. Georgieva, T.F. Ramlall, P.P. Borbat, J.H. Freed, D. Eliezer, J. Biol. Chem. 285, 28261-28274 (2010).
Structural Dynamics of Bio-Macromolecules by NMR: The Slowly Relaxing Local Structure Approach, E. Meirovitch, Y.E. Shapiro, A. Polimeno, J.H. Freed, Progress in NMR Spectroscopy, 56, 360-405 (2010).
Structure of the Ternary Complex Formed by a Chemotaxis Receptor Signaling Domain, the CheA Histidine Kinase and the Coupling Protein CheW as Determined by Pulsed Dipolar ESR Spectroscopy, J. Bhatnagar, P.P. Borbat, A.M. Pollard, A.M. Bilwes, J.H. Freed, B.R.Crane, Biochemistry, 49, 3824-3841 (2010).
ESR Microscopy for Biological and Biomedical Applications; C.S. Shin, C.R. Dunnam, P.P. Borbat, B. Dzikovski, E.D. Barth, H.J. Halpern, J.H. Freed, Nanoscience & Nanotechnology Letters 3, 561-567 (2011).
Stochastic Methods for Magnetic Resonance Spectroscopies, A. Polimeno, V. Barone, J.H. Freed, in “Computational Strategies for Spectrocopy”, Ed. V. Barone (Wiley, NY, Ch. 12, pp. 549-582 (2012).
A 2D-ELDOR Study of Heterogeneity and Domain Structure Changes in Plasma Membrane Vesicles, upon Cross-Linking of Receptors, Y.-W. Chiang, A. Costa-Filho, B.A. Baird, J.H. Freed, J. Phys. Chem. B 115, 10462-10469 (2011).
Locating a Lipid at the Portal to the Lipoxygenase Active Site, B.J. Gaffney, M. Bradshaw, S. Frausto, J.H. Freed, P. Borbat, Biophys. J. 103, 2134-2144 (2012).
Conformational Ensemble of the Sodium Coupled Aspartate Transporter, E. Georgieva, P.P. Borbat, C. Ginter, J.H. Freed, O. Boudker, Nature Struct. and Molec. Biology 20, 215-221 (2013).
Improved Sensitivity for Long-Distance Measurements in Biomolecules: Five-Pulse Double Electron-Electron Resonance, P.P. Borbat, E.R. Georgieva, J.H. Freed, J. Phys. Chem. Letts. 4, 170-175 (2013).
Pulse Dipolar ESR: Distance Measurements, P.P. Borbat and J.H. Freed in: Structure and Bonding, Vol. 152, J. R. Harmer and C.R. Timmel, Eds. (Springer, Heidelberg, Germany, New York USA), Ch. 1, 1-82 (2014).
HIV gp41 Fusion Peptide Increases Membrane Ordering in a Cholesterol Dependent Fashion, A.L. Lai, J.H. Freed, Biophysical Journal 106, 172-181 (2014).
Bacterial Chemoreceptor Dynamics Correlate with Activity State and are Coupled over Long Distances, D. Samanta, P.P. Borbat, B. Dzikovski, J.H. Freed, B.R. Crane, PNAS, 112, 2455-2460 (2015).
Two-Dimensional Electron-Electron Double Resonance and Molecular Motions: The Challenge of Higher Frequencies, J. Franck, S. Chandrasaken, B. Dzikovski, J.H. Freed ,J. Chem. Phys., 142, 212302-212316 (2015).