title: Monitoring of cholesterol oxidation in a lipid bilayer membrane using streptolysin O as a sensing and signal transduction element.
abstract: Streptolysin O (SLO), which recognizes sterols and forms nanopores in lipid membranes, is proposed as a sensing element for monitoring cholesterol oxidation in a lipid bilayer. The structural requirements of eight sterols for forming nanopores by SLO confirmed that a free 3-OH group in the β-configuration of sterols is required for recognition by SLO in a lipid bilayer. The extent of nanopore formation by SLO in lipid bilayers increased in the order of cholestanol<cholesterol<25-OH cholesterol and in a sterol concentration-dependent manner. The immobilization of liposomes consisting of PC, cholesterol and 4-cholesten-3-one exhibited a linear relationship between calcein permeability and the molar ratio of cholesterol and 4-cholesten-3-one. The SLO-based method was successfully applied for monitoring of cholesterol oxidase-mediated oxidation of cholesterol in a lipid bilayer. The potential of the SLO nanopore-based method for monitoring cholesterol oxidation in a lipid bilayer by other oxidative enzymes is also discussed.
authors.affiliation: Tokyo University Pharmacy and Life Science, 1432-1 Hachioji, Horinouchi, Tokyo 192-0392, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shoji
authors.affiliation: Tokyo University Pharmacy and Life Science, 1432-1 Hachioji, Horinouchi, Tokyo 192-0392, Japan.
authors.forename: Kana
authors.initials: K
authors.lastname: Ikeya
authors.affiliation: Tokyo University Pharmacy and Life Science, 1432-1 Hachioji, Horinouchi, Tokyo 192-0392, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Aoyagi
authors.affiliation: Department of Chemistry, College of Humanities and Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Takatsuji
authors.affiliation: Tokyo University Pharmacy and Life Science, 1432-1 Hachioji, Horinouchi, Tokyo 192-0392, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Yanagida
authors.affiliation: Tokyo University Pharmacy and Life Science, 1432-1 Hachioji, Horinouchi, Tokyo 192-0392, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Shibusawa
authors.affiliation: Department of Chemistry, College of Humanities and Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan. Electronic address: sugawara@chs.nihon-u.ac.jp.
authors.forename: Masao
authors.initials: M
authors.lastname: Sugawara
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D002784:Cholesterol / Q000032:analysis* / Q000378:metabolism*; D002789:Cholesterol Oxidase / Q000378:metabolism; D005452:Fluoresceins / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D058608:Nanopores; D010084:Oxidation-Reduction; D015398:Signal Transduction; D013261:Sterols / Q000737:chemistry / Q000378:metabolism; D013301:Streptolysins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D005452:Fluoresceins; D008051:Lipid Bilayers; D008081:Liposomes; D013261:Sterols; D013301:Streptolysins; C025964:streptolysin O; D002784:Cholesterol; D002789:Cholesterol Oxidase; C007740:fluorexon
keywords: Cholesterol; Cholesterol oxidase; Fluorometric permeability assay; Immobilized liposome membrane; Streptolysin O