AVS 46th International Symposium
    Biomaterial Interfaces Group Tuesday Sessions
       Session BI-TuP

Paper BI-TuP21
Incorporation of Membrane Proteins into Lipid Bilayers Supported on a SiO@sub 2@-surface.

Tuesday, October 26, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: A. Persson, Chalmers Univ. of Tech. and Göteborg Univ., Sweden
Authors: A. Persson, Chalmers Univ. of Tech. and Göteborg Univ., Sweden
F. Höök, Chalmers Univ. of Tech. and Göteborg Univ., Sweden
J Rydström, Chalmers Univ. of Tech. and Göteborg Univ., Sweden
B. Kasemo, Chalmers Univ. of Tech. and Göteborg Univ., Sweden
Correspondent: Click to Email
Transmembrane proteins are difficult to study in their native state, since detergents are used for the solubilization of transmembrane proteins, which might influence the protein properties and function. One way to circumvent this is to incorporate the proteins into lipid membranes deposited on solid supports. The focus of this project is to combine spontaneous formation of lipid membranes on solid supports, known to occur on SiO@sub 2@, with incorporation of transmembrane proteins. Understanding and mastering of this process has important implications for the development of biosensors and biomaterials, for investigations of the respiratory chain, studies of the photosynthesis, and in neurobiology. Small unilammellar vesicles (SUV's) form a lipid bilayer on hydrophilic SiO@sub 2@-surfaces.@footnote 1@ This process is most likely a two-stage process, where initially intact vesicles adsorb at the surface at low coverages. When a certain surface-concentration of SUV's is reached, the vesicles break and form a fluid bilayer. The protein containing SUV's studied in this work seem to behave in the same way. The SUV's were prepared by sonicating different phospholipids in buffer, and the proteins were incorporated with detergent. The vesicle and protein adsorption is studied with a new QCM-D technique where the frequency shift (mass adsorbed on the surface) and the energy dissipation shift (reflecting the viscoelastic properties of the overlayer) are measured simultaneously.@footnote 2@ The presence of the proteins in the supported bilayer is, after deposition, directly measured using the QCM-D technique, combined with a secondary process using specific monoclonal antibodies to the membrane bound proteins. The preparation procedures and the first results are presented. @FootnoteText@ @footnote 1@Keller, C. A., et al. 1998. Biophys. J. Vol 75 p.1397 @footnote 2@Rhodahl, M., et al. 1995. Rev. Sci.Instrum. Vol 66 p.3924.