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 Title: Nuclear Magnetic Resonance Studies of Model and Biological Membranes Author(s): Bowers, John Leland Department / Program: Chemistry Discipline: Chemistry Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: Ph.D. Genre: Dissertation Subject(s): Chemistry, Physical Abstract: High-field proton MASS is shown to yield high resolution $\sp1$H NMR spectra from a smectic, nematic, and hexagonal-II phase liquid crystals. Isotropic chemical shifts, order parameters, and relaxation times can be determined from these spectra. Such experiments are possible because of the special form of the dipolar Hamiltonian. The resolution in proton spectra is comparable to that obtained in sonicated systems using conventional NMR techniques. Carbon-13 MASS NMR spectra, of fluid and solid phases, are well resolved. In some cases, resonances are observed in MASS NMR spectra which are not observed in sonicated systems. A combination of CP-MASS with deuterated and undeuterated lipids allows the observation of the effects of sterols on bilayers. Proton MASS NMR spectra of the biological membranes, rod outer segments and purple membranes are reported along with the $\sp$C MASS NMR spectra of lung surfactant and myelin. We also have obtained $\sp2$H, $\sp$C, and $\sp$N NMR spectra of labelled amino acids incorporated into the membrane protein, bacteriorhodopsin, of Halobacterium halobium. Our results indicate that there are at least two motional classes of amino acids in bacteriorhodopsin. The first type are rigid and give rise to the broad powder pattern observed. These amino acids are "matrix" amino acids within the bilayer. The second type are mobile and give rise to the narrow "isotropic" solution spectra observed. These amino acids are located in the surface region of bacteriorhodopsin. Issue Date: 1988 Type: Text Description: 183 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988. URI: http://hdl.handle.net/2142/70407 Other Identifier(s): (UMI)AAI8823083 Date Available in IDEALS: 2014-12-15 Date Deposited: 1988
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