(444g) Effect of Membrane Fluctuation on Protein Adsorption to Lipid Membranes

The use of lipid membranes is expected as a material for artificial organs and biosensors. There are problems including such as reduction of antithrombogenicity due to protein adsorption and deterioration of durability of the material. It has been shown that the lipid membrane has a planar membrane immobilized on a substrate and a vesicle which is a closed vesicle composed of a lipid bilayer membrane. Their adsorption amount of the protein depends on the assembled form of lipid membranes. Lipid planar membranes are considered to be more stable than vesicles, but it is probable that the amount of protein adsorption is smaller than that of vesicles. Therefore, in this research, in order to clarify this implication we measured the adsorption amount of protein. And, we discussed the difference of adsorption behavior depends on the types of lipid membranes. Specially the effect of membrane fluctuation is addressed. We used not only phospholipids derived from biological membranes but also surfactants (SDBS, AOT etc) that can be produced in large quantities. Interaction between proteins and lipid membranes was investigated by preparing planar membranes and vesicles and comparing the adsorption and adsorption areas of proteins to them. As a result, it was suggested that the adsorption amount of protein to the lipid membrane prepared with the surfactant was larger than that of the phospholipid, and that the adsorption amount of the vesicle membrane was larger than that of the planar membrane. We discussed the enhanced effect of protein adsorption based on the membrane fluctuation. It was therefore suggested that if the vesicle membrane could be stabilized, it would be a more functional sensor material.