Shoji Atsushi, Ikeya Kana, Aoyagi Miki, Takatsuji Ryutaro, Yanagida Akio, Shibusawa Yoichi, Sugawara Masao
Tokyo University Pharmacy and Life Science, 1432-1 Hachioji, Horinouchi, Tokyo 192-0392, Japan.
Department of Chemistry, College of Humanities and Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
J Pharm Biomed Anal. 2016 Sep 5;128:455-461. doi: 10.1016/j.jpba.2016.06.009. Epub 2016 Jun 8.
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.
链球菌溶血素O（SLO）可识别固醇并在脂质膜中形成纳米孔，被提议作为监测脂质双层中胆固醇氧化的传感元件。八种固醇形成SLO纳米孔的结构要求证实，固醇β构型中的游离3-OH基团是SLO在脂质双层中识别所必需的。SLO在脂质双层中形成纳米孔的程度按胆甾烷醇<胆固醇<25-羟基胆固醇的顺序增加，且呈固醇浓度依赖性。由PC、胆固醇和4-胆甾烯-3-酮组成的脂质体的固定化显示，钙黄绿素渗透率与胆固醇和4-胆甾烯-3-酮的摩尔比之间存在线性关系。基于SLO的方法成功应用于监测脂质双层中胆固醇氧化酶介导的胆固醇氧化。还讨论了基于SLO纳米孔的方法用于监测其他氧化酶在脂质双层中胆固醇氧化的潜力。
