Theoretical study on microdomains in biomembranes

生物膜微区的理论研究

• 批准号: 15540395
• 负责人: KOMURA Shigeyuki
• 金额: $ 1.73万
• 依托单位: Tokyo Metropolitan University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15540395/
• 关键词: microdomain; raft; lipid; cholesterol; soft matter; 生体膜; 相分離; ランダウ自由エネルギー

In an effort to understand "rafts" in biological membranes, we propose phenomenological models for saturated and unsaturated lipid mixtures, and lipid plus cholesterol mixtures. We consider simple couplings between the local composition and internal membrane structure, and their influence on transitions between liquid and gel membrane phases. Assuming that the gel transition temperature of the saturated lipid is shifted by the presence of the unsaturated lipid, and that cholesterol acts as an external field on the chain melting transition, a variety of phase diagrams are obtained. Our results also apply to regions in the ternary phase diagram of lipid/lipid/cholesterol systems.We propose models for the first-order unbinding transition of lyotropic lamellae in surfactant solutions. The coupling between the surfactant volume fraction and the elastic degree of freedom is considered so that the net attractive interaction between the surfactant molecules is enhanced. The elastic degree of freedom can be either (i) a membrane elastic degree of freedom, or (ii) a bulk elastic degree of freedom. The phase behaviors of these two models are analyzed. For the both cases, the unbinding transition becomes first-order when the coupling is strong enough. We determine the associated preunbinding line which separates two lamellar phases having different repeat distances.

在努力了解“筏”在生物膜，我们提出了饱和和不饱和的脂质混合物，脂质加胆固醇的混合物的现象学模型。我们认为简单的本地组合物和内部的膜结构之间的耦合，和它们的液体和凝胶膜相之间的过渡的影响。假设的凝胶转变温度的饱和脂质的不饱和脂质的存在下移动，和胆固醇作为一个外部字段上的链熔融转变，得到各种相图。我们的结果也适用于区域的脂质/脂质/胆固醇系统的三元相图。我们提出了模型的溶致液晶在表面活性剂溶液中的一级非结合转变。表面活性剂的体积分数和弹性自由度之间的耦合被认为是使表面活性剂分子之间的净吸引相互作用增强。弹性自由度可以是（i）膜弹性自由度，或（ii）体弹性自由度。分析了这两种模型的相行为。对于这两种情况，当耦合足够强时，非束缚跃迁变为一阶跃迁。我们确定了相关的preunbinding线分离两个层状相具有不同的重复距离。

项目成果

Buckling of spherical shells adhering onto a rigid substrate

• DOI: 10.1140/epje/e2005-00038-5
• 发表时间: 2005-11-01
• 期刊: EUROPEAN PHYSICAL JOURNAL E
• 影响因子: 1.8
• 作者: Komura, S;Tamura, K;Kato, T
• 通讯作者: Kato, T

Effects of shear flow on structures of lamellar phase in a nonionic surfactant/water system

• DOI: 10.1007/b100297
• 发表时间: 2004
• 期刊: Progress in colloid and polymer science
• 作者: T. Kato;K. Minewaki;K. Miyazaki;Y. Kawabata;T. Shikata;S. Komura;Masatoshi Fujii

Phase Behavior of Charged Lipid Bilayer Membranes with Added Electrolyte

添加电解质的带电脂质双层膜的相行为

• 发表时间: 2003
• 期刊: J. Chem. Phys 119
• 作者: S.Komura;H.Shirotori;T.Kato
• 通讯作者: T.Kato

Phase Behavior of Three-Component Lipid Mixtures

三组分脂质混合物的相行为

• 发表时间: 2005
• 期刊: J. Phys. : Condens. Matter 17
• 作者: S.Komura;H.Shirotori;P.D.Olmsted
• 通讯作者: P.D.Olmsted

Polymer-Confinement-Induced Nematic Transition of Microemulsion Droplets

聚合物约束诱导的微乳液液滴向列相转变

• 发表时间: 2005
• 期刊: Europhys.Lett. 71
• 作者: K.Nakaya;M.Imai;S.Komura;T.Kawakatsu;N.Urakami
• 通讯作者: N.Urakami