孔隙形成与通过脂质膜的离子运输相结合,由跨膜离子电荷不平衡诱导:原子学分子动力学研究
Andrey A Gurtovenko1, Ilpo Vattulainen
1Laboratory of Physics and Helsinki Institute of Physics, Helsinki University of Technology, P.O. Box 1100, FI-02015 HUT, Finland. agu@fyslab.hut.fi
Journal of the American Chemical Society
|December 15, 2005
概括
离子电荷波动驱动脂质膜中的水孔形成,使离子运输和孔密封成为可能. 这揭示了无蛋白膜中离子泄漏的关键机制.
科学领域:
- 生物物理学的生物物理.
- 膜生物物理学 膜生物物理学
- 计算生物物理学的计算生物物理学
背景情况:
- 脂膜可以控制离子通道.
- 暂时的水孔可以在脂质双层中形成.
- 了解离子运输机制至关重要.
研究的目的:
- 通过脂膜中的短暂水孔研究离子运输.
- 阐明离子电荷不平衡在孔隙形成和动态中的作用.
- 确定影响孔隙密封和离子泄漏的因素.
主要方法:
- 原子规模的分子动力学模拟.
- 模拟通过脂质膜的离子运输.
- 在离子电荷不平衡下分析孔形成和动态.
主要成果:
- 通过膜的离子电荷不平衡导致水孔的形成.
- 通过毛孔的离子运输减少了跨膜潜力,导致毛孔密封.
- 离子电荷波动对于自发孔隙形成和离子泄漏至关重要.
结论:
- 自发的水孔形成和离子运输是由离子电荷波动驱动的.
- 通过无蛋白质脂质膜的离子泄漏是由短暂的孔隙介导的.
- 这些发现提供了关于膜透性和稳定性的见解.
相关概念视频
Ion Channels
The movement of ions like sodium, potassium, and calcium into and out of the cell is essential to maintain the electrochemical gradient in living cells. The ion channels—a class of membrane transport proteins—help maintain this ionic gradient for the smooth functioning of physiological activities such as maintaining cell size and volume, conducting nerve impulses, and gas and nutrient exchange.
Ion channels are specialized integral membrane proteins on the plasma membrane that allow specific...
Ion channels are specialized integral membrane proteins on the plasma membrane that allow specific...
Protein Diffusion in the Membrane
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
The Significance of Membrane Transport
The transport of solutes across the cell membrane is essential for metabolic processes, like maintaining cell size and volume, generating the action potential, exchanging nutrients and gases, etc. Membrane transport can be either passive or active. It can be simple diffusion, facilitated, or mediated transport aided by transport proteins such as transporters and channels.
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Mechanisms of Membrane Domain Formation
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
Pore Transport and Ion-Pair Transport
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
Facilitated Diffusion
The plasma membrane, a critical structure in cellular biology, houses an array of transporters, or carrier proteins, interspersed within its lipid bilayer. These proteins play a crucial role in solute transport through facilitated diffusion, a form of passive diffusion that uses transporters to move the molecules across the membrane.
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...
In this process, substrates such as organic compounds and ions interact with a transporter on one side, triggering conformational changes in proteins that enable...


