Geometrical and dynamical effects on NOE in macromolecules
Abstract
The transfer of non-equilibrium longitudinal magnetization (NOE) through a system of homonuclear spins is studied for several geometries, which admit analytical solutions, including the general three spin system and larger systems possessing periodic or nearly periodic structure. Also the effect of chemical exchange on NOE is examined. The results of these studies include (1) quantitative estimates of errors expected when NOE is used to determine molecular structure, (2) a rigorous mathematical formalism of spin diffusion including expressions for the range, lifetime, and diffusion constant of a system, together with their dependence on asymmetry, and (3) a simple procedure for calculating the NOE of a system undergoing rapid chemical exchange. NOE data for ATP exchanging between enzyme-bound and free forms is analyzed resulting in molecular structures for ATP bound to pyruvate kinase and methionyl tRNA synthetase. These structures are compared with previously published results.
Degree
Ph.D.
Advisors
Rao, Purdue University.
Subject Area
Nuclear physics
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