高トランスメブランポテンシャルでフォスフォリピド二重層のナノ孔形成とフォスファディチルセリンの外部化
P Thomas Vernier1, Matthew J Ziegler, Yinghua Sun
1MOSIS, Information Sciences Institute, Viterbi School of Engineering, University of Southern California, Marina del Rey, California 90292, USA. vernier@mosis.org
Journal of the American Chemical Society
|May 11, 2006
まとめ
分子ダイナミクスのシミュレーションでは,電気パルスが細胞膜に素早く孔を開け,フォスファティジルセリン (PS) が細胞の外部に移動することを可能にすることを示しています. これは,電場が細胞膜の構造と機能にどのように影響するかを説明します.
科学分野:
- バイオフィジックス 生物物理学
- 細胞生物学 細胞生物学
- コンピュータ生物学 コンピュータ生物学
背景:
- フォスファティディルセリン (PS) の外部化は,アポプトーシスと細胞損傷の重要な指標です.
- ナノ秒パルス電場 (nsPEF) などの強い電場への曝露は,膜の孔隙とPSの外化を引き起こす可能性があります.
研究 の 目的:
- 電気場によって誘発される膜孔とフォスファティディルセリン (PS) 輸送の原子レベルのメカニズムを調査する.
- 分子動力学シミュレーションとnsPEFに対する細胞膜反応の実験観察を相関させる.
主な方法:
- 7%PS.を含む脂質バイレイヤの原子解像度の分子動力学シミュレーション.
- 模擬電場 (450 mV/nm) を適用して,膜の孔隙を誘導する.
主要な成果:
- ナノメートルの直径の水性毛穴の急速な形成は,電場アプリケーションのナノ秒以内に発生します.
- 孔形成の過程で,アニオンのPSヘッドグループが,形成中の水性性孔面に沿って電泳的に運ばれる.
結論:
- 分子ダイナミクスシミュレーションは,nsPEF誘発の膜ポレーションとPS外部化に関する実験的発見を裏付けている.
- この研究は,電気場が脂質二重層の孔形成とイオン輸送をどのように駆動するかのメカニズム的理解を提供します.
関連する概念動画
01:54What are Membranes?
A key characteristic of life is the ability to separate the external environment from the internal space. To do this, cells have evolved semi-permeable membranes that regulate the passage of biological molecules. Additionally, the cell membrane defines a cell’s shape and interactions with the external environment. Eukaryotic cell membranes also serve to compartmentalize the internal space into organelles, including the endomembrane structures of the nucleus, endoplasmic reticulum and Golgi...
01:24What are Membranes?
A cell's plasma membrane demarcates the cell's borders and determines the nature of its interaction with the environment. Cells exclude certain substances, take in others, and excrete some others in controlled quantities. The plasma membrane must be flexible to allow certain cells, such as red and white blood cells, to change their shape while passing through narrow capillaries. These are the more obvious plasma membrane functions. In addition, the plasma membrane's surface carries markers that...
01:19Fluid Mosaic Model
Scientists identified the plasma membrane in the 1890s and its principal chemical components (lipids and proteins) by 1915. The model for plasma membrane structure, proposed in 1935 by Hugh Davson and James Danielli, was the first model to be widely accepted in the scientific community. The model was based on the plasma membrane's "railroad track" appearance in early electron micrographs. Davson and Danielli theorized that the plasma membrane's structure resembled a sandwich with the analogy of...
01:18Membrane Domains
The membrane domains concentrate specific lipids and proteins at one place within the membrane, which helps in cell signaling, adhesion, and other critical cellular processes. These domains can differ in size, composition, function, and lifespan.
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
Protein Domains
The membrane comprises a group of distinct proteins responsible for carrying out a cell's specific function. For example, the plasma membrane of the human sperm, or a single germ cell, contains a unique set of proteins in the anterior...
01:28The Inner Mitochondrial Membrane
The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria. In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
00:59Mechanisms of Membrane Domain Formation
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...