Surface Analytical Studies of Gramicidin A in Biomimetic Model Membrane Systems
This thesis is an investigation of the properties of gramicidin A in model membrane systems. This study investigates a solid supported bilayer lipid membrane comprised of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and gramicidin A deposited on a thioglucose modified Au(111) electrode. A “floating” bilayer lipid membrane was also investigated that was composed of DMPC, cholesterol, glycolipid monosialoganglioside (GM1), and gramicidin A deposited on a thioglucose modified Au(111) electrode. The GM1 was used as a spacer molecule to create a water reservoir between the modified electrode and lipid bilayer. Polarization modulation infrared reflection adsorption spectroscopy (PM-IRRAS) was used to investigate the solid supported and the floating bilayer lipid membrane. The PM-IRRAS studies were completed to probe the electric field driven changes in the orientation and conformation of gramicidin A in the lipid bilayer. Atomic force microscopy was used to investigate the topography and thickness of the floating bilayer lipid membrane system.