Nuclear Magnetic Resonance Studies of Model and Biological Membranes

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.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Bowers, John Leland

• Chemistry, Physical

Identifier

(UMI)AAI8823083

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/70407