COLL 536 |
| Eugene J. Choi and Emilios K. Dimitriadis. Instrumentation and Research Development Resource, Division of Bioengineering and Physical Science, ORS, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892 |
| The adsorption of membrane-associated protein cytochrome C to anionic lipid bilayers of dioleoyl phosphatidylglycerol (DOPG) was studied in low ionic strength physiological buffer using atomic force microscopy (AFM). The bilayers were supported on polylysinated-mica. The formation of stable, single lipid bilayers was confirmed by imaging and force spectroscopy. Upon addition of cytochrome C, there are no apparent topographical changes of the bilayer surface. Instead, both AFM images and force spectroscopy curves suggest that the protein interpenetrates into the bilayer and significantly lowers the force required to penetrate the bilayer with the probe tip. Mass spectroscopy confirmed the presence of cytochrome C in the lipid bilayers. These results suggest that 1) hydrophobic interactions dominate electrostatic forces during cytochrome c adsorption to DOPG bilayers, and 2) cytochrome C insertion changes the mechanical properties of the bilayer. |
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Nanoscience and Nanotechnology
2:00 PM-5:15 PM, Thursday, April 1, 2004 Marriott -- Orange County 5, Oral
Division of Colloid and Surface Chemistry |