title: Measurement of membrane tension of free standing lipid bilayers via laser-induced surface deformation spectroscopy.
abstract: Non-invasive measurement of the membrane tension of free-standing black lipid membranes (BLMs), with sensitivity on the order of μN m(-1), was achieved using laser-induced surface deformation (LISD) spectroscopy. A BLM was vertically formed via the folding method and aqueous phases with different refractive indices were added on each side in order to induce radiation pressure by a laser beam. The dynamic response of the deformed BLMs was measured under periodic intensity modulation and their tensions could be estimated. The dependence of membrane tension on the cholesterol concentration of BLMs composed of phosphatidylcholine and phosphatidylethanolamine was investigated, with the membrane tension increasing from 1.3 μN m(-1) to 68.1 μN m(-1) when the cholesterol concentration increased from zero to 33%. These tension values are much smaller than some of those previously reported, because this method does not suppress membrane fluctuation unlike other conventional methods. Our LISD system can be a promising tool for the measurement of membrane tension in BLMs.
authors.affiliation: Department of Applied Chemistry and Biotechnology, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan. fujinami@faculty.chiba-u.jp.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Takei
authors.affiliation: Department of Applied Chemistry and Biotechnology, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan. fujinami@faculty.chiba-u.jp.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Yaguchi
authors.affiliation: Department of Applied Chemistry and Biotechnology, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan. fujinami@faculty.chiba-u.jp.
authors.forename: Takuya
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Department of Applied Chemistry and Biotechnology, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan. fujinami@faculty.chiba-u.jp.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Nomoto
authors.affiliation: Department of Basic Science, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Toyota
authors.affiliation: Department of Applied Chemistry and Biotechnology, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan. fujinami@faculty.chiba-u.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Fujinami
mesh_terms: D002784:Cholesterol / Q000737:chemistry; D007834:Lasers; D008051:Lipid Bilayers / Q000737:chemistry* / Q000528:radiation effects; D010713:Phosphatidylcholines / Q000737:chemistry; D013314:Stress, Mechanical
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D002784:Cholesterol