细胞膜结构及探索历程
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第四章
细胞质膜
细胞膜结构及探索历程
本章内容
• 细胞质膜的结构模型 • 生物膜基本特征与功能 • 膜骨架
细胞膜结构及探索历程
细胞膜结构及探索历程
• 细胞质膜在维持胞内环境的相对稳定，
细胞与环境之间的物质运输、能量转换 及信息传递过程中有重要作用。
• 细胞内膜wenku.baidu.com统和细胞质膜统称为生物膜。
细胞膜结构及探索历程
细胞膜结构及探索历程
• 脂质体：
具有亲水和疏水两性的脂类物质在水相中形成 的、由脂双层构成的人工膜结构叫做脂质体。
• 作用：
研究膜脂和膜蛋白及其生物学性质 作为转基因的介质，将DNA导入细胞。 作为药物载体在活体内给药，治疗疾病。
细胞膜结构及探索历程
（二）膜蛋白： 主要承担和执行生物膜的功能。不同功能的
(1)膜的流动性，膜蛋白和膜脂均可以侧向运动。 The core lipid bilayer exists in a fluid state, capable of dynamic movement.
(2)膜蛋白分布的不对称性，以镶嵌、覆盖或贯穿 的形式与脂双层分子结合。 Membrane proteins form a mosaic of particles penetrating the lipid to varying degrees.
Figure. Liposomes（脂质体） (A) An electron micrograph of unfixed, unstained phospholipid vesicles (liposomes) in water. The bilayer structure of the vesicles is readily apparent. (B) A drawing of a small spherical liposome seen in cross-section. Liposomes are commonly used as model membranes in experimental studies.
细胞，其膜蛋白的含量和种类有显著差异。
• 按照功能划分为：
催化代谢类：参与催化的酶 物质运输类：泵、载体、通道 信息的感受和传递类：受体、抗原、黏附分子
细胞膜结构及探索历程
Membrane proteins
Figure. Six ways in which membrane proteins associate with the lipid bilayer. Most trans-membrane proteins are thought to extend across the bilayer
dogma” of membrane biology.
The Fluid Mosaic Model, proposed in 1972 by Singer and Nicolson, had two key feat细ur胞e膜s结, b构o及t探h索i历m程plied in its name.
流动镶嵌模型的要点
细胞膜结构及探索历程
Figure. The parts of a phospholipid molecule. Phosphatidylcholine （PC,磷脂酰胆碱）, represented schematically (A), in formula (B), as a
space-filling model (C), and as a symbol (D). The kink due to the cisdouble bond（顺双键） is ex细a胞g膜ge结r构a及te探d索i历n程these drawings for emphasis.
S.J.Singer and G.Nicolson(1972): fluid-mosaic model;
K.Simons et al(1997): lipid rafts model;
细胞膜结构及探索历程
细胞膜结构及探索历程
Singer and Nicolson’s Model of membrane structure: The fluid-mosaic model is the “central
structures is formed. Wedge-shaped lipid molecules (above) form
micelles, whereas cylinder-shaped phospholipid molecules (below) form
bilayers.
细胞膜结构及探索历程
Figure. A lipid micelle（微囊） and a lipid bilayer seen in cross-
section（横断面）. Lipid molecules form such structures spontaneously
in water. The shape of the lipid molecule determines which of these
第一节 细胞质膜的结构模型
一、生物膜的结构模型： 1 质膜结构研究历史的回顾：
细胞膜结构及探索历程
Overton(1890s): Lipid nature of PM;
J.D.Robertson(1959): The TEM showing:the trilaminar appearance of PM; Unit membrane model;
as a single a helix (1) or as multiple a helices (2); some of these “single-pass” and “multipass” proteins have a covalently attached fatty acid chain inserted in the cytoplasmic monolayer (1). Other membrane proteins are attached to the bilayer solely by a covalently attached lipid - either a fatty acid chain or prenyl group - in the cytoplasmic monolayer (3) or, less often, via an oligosaccharide, to a minor phospholipid, phosphatidylinositol(磷脂酰肌醇), in the noncytoplasmic monolayer (4). Finally, many proteins are attached to the membrane only by noncovalent interactions with other membrane proteins (5) and (6).
细胞膜结构及探索历程
• 目前对生物膜结构的认识 P85
要点1： 磷脂分子的排列形式 要点2：蛋白质与磷脂分子的关系 要点3：对生物膜的整体认识
细胞膜结构及探索历程
二、生物膜的成分：
（一）膜脂: 生物膜的基本组成成分，主要包括的类型有： 磷脂：膜脂的基本成分，含量＞50% 糖脂：含量＜5% 胆固醇：含量 ＜1/3
细胞质膜
细胞膜结构及探索历程
本章内容
• 细胞质膜的结构模型 • 生物膜基本特征与功能 • 膜骨架
细胞膜结构及探索历程
细胞膜结构及探索历程
• 细胞质膜在维持胞内环境的相对稳定，
细胞与环境之间的物质运输、能量转换 及信息传递过程中有重要作用。
• 细胞内膜wenku.baidu.com统和细胞质膜统称为生物膜。
细胞膜结构及探索历程
细胞膜结构及探索历程
• 脂质体：
具有亲水和疏水两性的脂类物质在水相中形成 的、由脂双层构成的人工膜结构叫做脂质体。
• 作用：
研究膜脂和膜蛋白及其生物学性质 作为转基因的介质，将DNA导入细胞。 作为药物载体在活体内给药，治疗疾病。
细胞膜结构及探索历程
（二）膜蛋白： 主要承担和执行生物膜的功能。不同功能的
(1)膜的流动性，膜蛋白和膜脂均可以侧向运动。 The core lipid bilayer exists in a fluid state, capable of dynamic movement.
(2)膜蛋白分布的不对称性，以镶嵌、覆盖或贯穿 的形式与脂双层分子结合。 Membrane proteins form a mosaic of particles penetrating the lipid to varying degrees.
Figure. Liposomes（脂质体） (A) An electron micrograph of unfixed, unstained phospholipid vesicles (liposomes) in water. The bilayer structure of the vesicles is readily apparent. (B) A drawing of a small spherical liposome seen in cross-section. Liposomes are commonly used as model membranes in experimental studies.
细胞，其膜蛋白的含量和种类有显著差异。
• 按照功能划分为：
催化代谢类：参与催化的酶 物质运输类：泵、载体、通道 信息的感受和传递类：受体、抗原、黏附分子
细胞膜结构及探索历程
Membrane proteins
Figure. Six ways in which membrane proteins associate with the lipid bilayer. Most trans-membrane proteins are thought to extend across the bilayer
dogma” of membrane biology.
The Fluid Mosaic Model, proposed in 1972 by Singer and Nicolson, had two key feat细ur胞e膜s结, b构o及t探h索i历m程plied in its name.
流动镶嵌模型的要点
细胞膜结构及探索历程
Figure. The parts of a phospholipid molecule. Phosphatidylcholine （PC,磷脂酰胆碱）, represented schematically (A), in formula (B), as a
space-filling model (C), and as a symbol (D). The kink due to the cisdouble bond（顺双键） is ex细a胞g膜ge结r构a及te探d索i历n程these drawings for emphasis.
S.J.Singer and G.Nicolson(1972): fluid-mosaic model;
K.Simons et al(1997): lipid rafts model;
细胞膜结构及探索历程
细胞膜结构及探索历程
Singer and Nicolson’s Model of membrane structure: The fluid-mosaic model is the “central
structures is formed. Wedge-shaped lipid molecules (above) form
micelles, whereas cylinder-shaped phospholipid molecules (below) form
bilayers.
细胞膜结构及探索历程
Figure. A lipid micelle（微囊） and a lipid bilayer seen in cross-
section（横断面）. Lipid molecules form such structures spontaneously
in water. The shape of the lipid molecule determines which of these
第一节 细胞质膜的结构模型
一、生物膜的结构模型： 1 质膜结构研究历史的回顾：
细胞膜结构及探索历程
Overton(1890s): Lipid nature of PM;
J.D.Robertson(1959): The TEM showing:the trilaminar appearance of PM; Unit membrane model;
as a single a helix (1) or as multiple a helices (2); some of these “single-pass” and “multipass” proteins have a covalently attached fatty acid chain inserted in the cytoplasmic monolayer (1). Other membrane proteins are attached to the bilayer solely by a covalently attached lipid - either a fatty acid chain or prenyl group - in the cytoplasmic monolayer (3) or, less often, via an oligosaccharide, to a minor phospholipid, phosphatidylinositol(磷脂酰肌醇), in the noncytoplasmic monolayer (4). Finally, many proteins are attached to the membrane only by noncovalent interactions with other membrane proteins (5) and (6).
细胞膜结构及探索历程
• 目前对生物膜结构的认识 P85
要点1： 磷脂分子的排列形式 要点2：蛋白质与磷脂分子的关系 要点3：对生物膜的整体认识
细胞膜结构及探索历程
二、生物膜的成分：
（一）膜脂: 生物膜的基本组成成分，主要包括的类型有： 磷脂：膜脂的基本成分，含量＞50% 糖脂：含量＜5% 胆固醇：含量 ＜1/3