单核生物强内向校正器K+通道Kir2.2的晶体结构,分辨率为3.1A
Xiao Tao1, Jose L Avalos, Jiayun Chen
1Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, Howard Hughes Medical Institute, 1230 York Avenue, New York, NY 10065, USA.
Science (New York, N.Y.)
|December 19, 2009
概括
对内向整形剂 (Kir2) 通道的结构洞察力揭示了离子结合点和独特的表面特征. 这项研究为了解通道功能和开发针对心律失常和治疗的向抑制剂提供了基础.
科学领域:
- 结构生物学 结构生物学
- 分子生理学分子生理学
- 离子通道研究研究
背景情况:
- 内向整形剂 (K+) 通道,特别是Kir2通道,对于调节刺激细胞中静止膜潜能至关重要.
- 由于突变导致的Kir2通道功能障碍与周期性和心律失常等严重疾病有关.
- 了解这些通道的结构对于阐明它们的功能和开发治疗策略至关重要.
研究的目的:
- 确定Kir2.2通道的晶体结构,为其功能提供分子基础.
- 为了确定道通路内的离子结合点,并将它们与电生理学数据相关联.
- 调查可能解释通道属性的结构特征,如整形和毒素不敏感性.
主要方法:
- 使用X射线结晶学来确定的结构Kir2.2.2.
- 结晶在各种离子的存在下进行,包括卢比 (Rb+), (Sr2+) 和欧洲 (Eu3+).
- 电生理学数据与结构性发现有着广泛的相关性.
主要成果:
- 肉Kir2.2的晶体结构,与人类Kir2.2高度同源,得到了阐明.
- 沿离子导电路确定了Rb+,Sr2+和Eu3+的特定结合点.
- 发现这些位点既具有导电性,又具有抑制性,为纠正提供了一个结构性的解释.
- 观察到独特的细胞外表面特征,包括结构化的塔楼和不寻常的选择性过器入口.
结论:
- 已确定的离子结合点为理解向内修正提供了结构基础.
- 独特的细胞外表面特征可能有助于真核细胞内向整流器对毒素的抗性.
- 这些结构特征表明开发不同基尔通道亚型的特定抑制剂的潜在途径.
相关概念视频
02:42Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
01:18ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
02:18X-ray Crystallography
The size of the unit cell and the arrangement of atoms in a crystal may be determined from measurements of the diffraction of X-rays by the crystal, termed X-ray crystallography.
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
01:26Voltage-gated Ion Channels
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...