控制通道中的离子选择性,通过碳联体的静电和动态特性来控制
Sergei Yu Noskov1, Simon Bernèche, Benoît Roux
1Department of Biochemistry & Structural Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, New York 10021, USA.
Nature
|October 16, 2004
概括
通道通过选择性地传导 (K+) 超过 (Na+) 来维持细胞离子平衡. 动态的,灵活的通道孔,而不仅仅是刚性适合,解释了这一关键的K +选择性.
科学领域:
- 生物物理学的生物物理.
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 通道对于细胞离子恒温至关重要.
- 它们对K+对Na+离子具有很高的选择性.
- 这种选择性传统上归因于通道孔内的精确结构适合.
研究的目的:
- 研究蛋白质灵活性和动态在通道离子选择性中的作用.
- 探索通道中K+和Na+离子之间的区分背后的分子机制.
主要方法:
- 使用了分子动力学 (MD) 模拟.
- 专注于KcsA通道结构.
- 分析了孔外层碳基团的动态和静电特性.
主要成果:
- 模拟显示了KcsA通道孔中的碳基组的动态",类似液体"的行为.
- 通过它们的静电性质,这些动态碳基团被证明可以控制离子选择性.
- 孔隙的灵活性是强大的K +选择性的关键因素.
结论:
- 通道选择性不仅仅取决于刚性结构的适合性.
- 灵活的协调群体的蛋白质动力学和静电场强度对于K+对Na+的歧视至关重要.
- 这项工作强调了生物离子运输中的动态相互作用的重要性.
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...
Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Ligand-gated Ion Channels
Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site.
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Non-gated Ion Channels
Ion channels are specialized proteins on the plasma membrane that allow charged ions to pass down their electrochemical gradient. Their main function is to maintain the membrane potential which is critical for cell viability. These channels are either gated or non-gated and can transport more than a thousand ions within milliseconds for the cellular event to occur.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
Ligand-Gated Ion Channel Receptor: Gating Mechanism
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
Ligand-gated Ion Channels
Ligand-gated ion channels are transmembrane proteins with a channel for ions to pass through and a binding site for a ligand. The channel opens only when a ligand attaches to the binding site.
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...
Three Subfamilies of Ligand-gated Ion Channels
Ligand-gated ion channels fall into three subfamilies. The 'Cys-loop' includes the nicotinic acetylcholine receptors, γ-aminobutyric acid (GABA), glycine, and 5-hydroxytryptamine receptors. The second one is the 'Pore-loop' channels that include the...


