まとめ
アラメチシンの結晶構造は,アンフィパティックなアルファヘリル状の形状を示しています. この構造は,内部が水性,外側は水害性の電圧ゲートイオンチャネルをモデルにしています.
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
- 膜タンパク質 膜タンパク質
背景:
- アラメシチンはペプチド抗生物質で,膜に毛穴を形成することが知られている.
- アラメチシンの正確な分子構造を理解することは,そのイオンチャネル機能を明らかにするために不可欠です.
研究 の 目的:
- 非水性溶媒におけるアラメチシンの高解像度結晶構造を決定する.
- アラメチシンベースの電圧ゲートイオンチャネルの分子モデルを開発する.
主な方法:
- 1.5-A解像度のX線結晶学. 解像度1.5-AのX線結晶学. 解像度1.5-AのX線結晶学.
- クリスタル構造の精製.
- イオンチャネルの計算モデリング.
主要な成果:
- 結晶構造は,アラメチシンが主にアルファヘリル状の形状を採用し,プロリン残留で曲がっていることを示しています.
- ヘリックスは高度にアンフィパティックで,極の原子は1つの表面帯に集中しています.
- ボルトゲートイオンチャネルのモデルは,表面の互補性,水性内側,水性外側を示しています.
- グルタミン残留物の水分化された環は,チャネル構造を安定させ,直径の制限を生み出します.
結論:
- 決定されたアラメチシン構造は,その毛孔形成機構を理解するための基礎を提供します.
- 分子モデルは,電圧誘導イオンチャネル形成と機能のメカニズムを示唆しています.
- 水素結合のグルタミン残基は,チャネル安定化とゲーティングにおいて重要な役割を果たします.
さらに関連する動画
11:42Reconstitution of a Transmembrane Protein, the Voltage-gated Ion Channel, KvAP, into Giant Unilamellar Vesicles for Microscopy and Patch Clamp Studies
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09:54Multifunctional, Micropipette-based Method for Incorporation And Stimulation of Bacterial Mechanosensitive Ion Channels in Droplet Interface Bilayers
Published on: November 19, 2015
関連する概念動画
01:24Non-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.
01:19Ligand-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...
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...
01:24Non-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.
01:30Ligand-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...
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...