Nuclear Magnetic Resonance in Chemistry

The Bryant laboratory utilizes a wide range of nuclear and electron spin resonance methods to characterize intra and intermolecular dynamics. A primary focus is the rich information available from the study of the magnetic field dependence of the nuclear spin-lattice relaxation rate as a function of the magnetic field strength or what is called the magnetic relaxation dispersion (MRD). We have constructed unique instrumentation that permits acquisition of MRD profiles for a variety of nuclear resonances in high resolution. These measurements provide a direct measure of the time fluctuations in various nuclear or nuclear-electron dipolar couplings. The resulting MRD profile reports relative inter and intramolecular motions over the time range from about ten microseconds to one picosecond. We are developing methods for probing the fluctuation spectrum of specific vectors defined in structurally interesting proteins and are trying to understand how these fluctuations affect molecular function. In related work, we apply the nuclear spin relaxation induced by freely diffusing paramagnetic solutes in cosolutes to define how one molecule samples the local environment of another and explores the surface or even penetrates into a complex structure like a folded protein. The measurements are sensitive to relatively weak intermolecular interactions and permit definition of highly localized intermolecular free energy differences in solutions. Multinuclear studies of proteins in a number of dynamical environments provide a fundamental characterization of how the protein structure fluctuates in time and how energy is redistributed in the folded structure. The practical implications range from understanding protein catalytic function to developing new techniques for diagnostic medicine in the context of magnetic resonance imaging or MRI.

Recent Publications

Water-proton-spin-lattice-relaxation dispersion of paramagnetic protein solutions. Diakova G, Goddard Y, Korb JP, Bryant RG. J Magn Reson. 208:195-203 (2010).

Water and backbone dynamics in a hydrated protein. Diakova G, Goddard YA, Korb JP, Bryant RG. Biophys J. 98:138-46 (2010).

Dynamics of water in and around proteins characterized by 1H Spin-Lattice Relaxometry. Bryant RG. Comptes Rendus Physique. 11(2), 128-135(2010).

Dimensionality of diffusive exploration at the protein interface in solution. Grebenkov DS, Goddard YA, Diakova G, Korb JP, Bryant RG. J Phys Chem B. 113, 13347-13356 (2009).

Water molecule contributions to proton spin-lattice relaxation in rotationally immobilized proteins. Goddard YA, Korb JP, Bryant RG. J Magn Reson. 199, 68-74 (2009).


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