電圧依存のK+チャネルのX線構造
Youxing Jiang1, Alice Lee, Jiayun Chen
1Howard Hughes Medical Institute, Laboratory of Molecular Neurobiology and Biophysics, Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
Nature
|May 2, 2003
まとめ
Aeropyrum pernix.から電圧依存のK+チャネル (KvAP) の構造を決定しました. ボルテージセンサーのペッダルの柔軟なヒンジは,細胞膜を横断してイオンを伝導するために移動することを示唆しています.
科学分野:
- 構造生物学 構造生物学とは
- バイオフィジックス 生物物理学
- 分子生物学は分子生物学である.
背景:
- 電圧に依存するK+チャネルは,神経と筋肉の電気活動に不可欠です.
- これらのチャネルは,細胞膜の電圧の変化に基づいてイオン伝導を調節します.
- その構造を理解することは,細胞の電気信号伝達の解明の鍵です.
研究 の 目的:
- Aeropyrum pernix.からのKVAPチャネルの高解像度の結晶構造を決定する.
- KvAPの電圧センサーメカニズムの構造的特徴を特徴づける.
- 電圧依存のカチオンチャネルのゲーティングメカニズムに関する洞察を提供するため.
主な方法:
- X線結晶学を用いて,全長KVAPチャネルの構造を3.2A解像度で決定した.
- 孤立した電圧センサードメインは結晶化し,1.9Aに解明されました.
- モノクローナルファブ断片は,チャネル複合体を安定させ,結晶化するために使用されました.
主要な成果:
- KvAPチャネル構造は,ユニークな"電圧センサーパドル"に囲まれた中央のイオン伝導孔を明らかにします.
- これらのパドルは,水性,カチオン性,ヘリックス・ターン・ヘリックス構造で,チャネルの外側辺りに位置しています.
- 弾圧センサーを毛穴に接続する柔軟なヒンジーを特定し,運動の可能性を示しました.
結論:
- 決定された構造は,電圧依存のK+チャネルの詳細な分子モデルを提供します.
- "電圧センサーパドル"と柔軟なヒンジーは,電圧に依存したゲーティングのための新しいメカニズムを提供します.
- この研究は,イオンチャネル機能と細胞電気生理学の理解を前進させる.
関連する概念動画
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.
Voltage-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...
G-Protein Gated Ion Channels
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...
Sensory organs,...
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.
Voltage-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...
Bewley Lattice Diagram
The Bewley lattice diagram, developed by L. V. Bewley, effectively organizes the reflections occurring during transmission-line transients. It visually represents how voltage waves propagate and reflect within a transmission line, making it easier to understand the complex interactions that occur.


