离子通道中的电压传感:一个50年的团解开了?
1Nobel Institute for Neurophysiology and Department of Neuroscience, Karolinska Institutet, SE-171 77, Stockholm, Sweden. petarhem@neuro.ki.se
Lancet (London, England)
|April 16, 2004
概括
电压离子通道具有新的S4螺旋运动,形成一个横扫脂质双层的. 这一发现挑战了现有的模型,并为药物开发的向道功能提供了新的途径.
科学领域:
- 神经科学是一个神经科学.
- 结构生物学 结构生物学
- 生物物理学的生物物理.
背景情况:
- 电压离子通道对于神经系统的电活动至关重要.
- 电压传感器区域中的S4螺旋控制通道门,但其运动机制仍在争论中.
- 之前的模型假设S4在蛋白质核中的运动.
研究的目的:
- 为了研究电压门通道门的结构基础.
- 为了阐明S4螺旋在通道打开和关闭期间的运动.
主要方法:
- 电压门通道的X射线晶体学.
- 电压传感器区域的结构分析.
主要成果:
- S4螺旋形成了一个从通道周围延伸的针头环.
- 这种结构表明一个""模型,其中S4横扫通过脂质双层.
- 这与之前的S4运动在蛋白质核中的模型相矛盾.
结论:
- 模型为S4螺旋运动在电压门通道中提供了新的视角.
- 这一发现可以解释脂溶性药物的作用,如麻醉剂和抗药.
- 需要进一步的研究来使这个模型与现有的实验数据相协调.
相关概念视频
Induced Electric Dipoles
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Drift Velocity
The high speed of electrical signals results from the fact that the force between charges acts rapidly at a distance. Thus, when a free charge is forced into a wire, the incoming charge pushes other charges ahead due to the repulsive force between like charges. These moving charges move the charges farther down the line. The density of charge in a system cannot easily be increased, so the signal is passed on rapidly. The resulting electrical shock wave moves through the system at nearly the...
DC Battery
A conductor needs to be a component of a path that creates a closed loop or full circuit to have a continuous current flowing through it. A current starts to flow if an electric field is created inside an isolated conductor that is not part of a full circuit. The conductor quickly develops a net positive charge at one end and a net negative charge at the other. These charges generate an electric field opposite the direction of the applied electric field, which reduces the current. Eventually,...
Ampere-Maxwell's Law: Problem-Solving
A parallel-plate capacitor with capacitance C, whose plates have area A and separation distance d, is connected to a resistor R and a battery of voltage V. The current starts to flow at t = 0. What is the displacement current between the capacitor plates at time t? From the properties of the capacitor, what is the corresponding real current?
To solve the problem, we can use the equations from the analysis of an RC circuit and Maxwell's version of Ampère's law.
For the first part of the problem,...
To solve the problem, we can use the equations from the analysis of an RC circuit and Maxwell's version of Ampère's law.
For the first part of the problem,...
Electrochemical Systems
Electrochemical systems provide a fascinating insight into the dynamic interplay of charged species within various phases. One notable example is the interaction between a membrane permeable to K⁺ ions but not to Cl⁻ ions, separating an aqueous KCl solution from pure water. As K⁺ ions diffuse through the membrane, they generate net charges on each phase, leading to a potential difference between them.Similarly, when a piece of Zn is immersed in an aqueous ZnSO₄ solution, the Zn metal, composed...
The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...


