胆固醇和多不和链在脂蛋白相互作用中的作用:在现实的膜环境中模拟罗多普辛的分子动力学模拟
Michael C Pitman1, Alan Grossfield, Frank Suits
1IBM T. J. Watson Research Center, 1101 Kitchawan Road, P.O. Box 218, Yorktown Heights, NY 10598, USA.
Journal of the American Chemical Society
|March 31, 2005
概括
分子动力学模拟揭示了罗多普辛 (一种膜蛋白) 如何改变脂质双层结构. 胆固醇分布补充了罗多普辛的作用.
科学领域:
- 生物物理学的生物物理.
- 分子生物学分子生物学
- 膜蛋白的动力学 膜蛋白的动力学
背景情况:
- 罗多普辛是一种关键的膜蛋白,参与视觉和G蛋白结合受体信号传递.
- 了解蛋白质-脂质相互作用对于膜蛋白的功能和稳定性至关重要.
- 众所周知,胆固醇可以调节膜性质和蛋白质活性.
研究的目的:
- 通过分子动力学模拟,研究罗多普辛与其脂质环境之间的分子级相互作用.
- 为了阐明罗多普辛如何扰乱脂质双层结构.
- 探索胆固醇在稳定罗多普辛中的作用.
主要方法:
- 118纳秒分子动力学 (MD) 模拟.
- 模拟了一种嵌入罗多素的脂质双层,其中含有脂 (1-斯泰尔-2-多可萨赫萨埃诺伊尔-酸盐胆[SDPC]和1-斯泰尔-2-多可萨赫萨埃诺伊尔-酸盐乙醇胺[SDPE]) 和胆固醇的特定混合物.
- 对脂质重定向,分布和与罗多普辛相互作用的分析.
主要成果:
- 罗多普辛破坏了脂质双层的横向和横向对称性.
- 罗多普辛附近的脂质重定位,不和链优先与蛋白质相互作用.
- 膜内的胆固醇分布补充了罗多普辛的横向形状,表明它具有稳定作用.
- 胆固醇稳定了罗多普辛的原生暗适应状态,而没有直接结合.
结论:
- 罗多普辛显著影响其周围的脂质双层组织.
- 胆固醇在稳定罗多普辛中发挥着关键作用,可能是通过脂质组织介导的间接相互作用.
- 模拟提供了一个分子基础,用于实验性观察胆固醇介导的罗多素稳定.
更多相关视频
相关概念视频
01:23Membrane Fluidity
Cell membranes are composed of phospholipids, proteins, and carbohydrates loosely attached to one another through chemical interactions. Molecules are generally able to move about in the plane of the membrane, giving the membrane its flexible nature called fluidity. Two other features of the membrane contribute to membrane fluidity: the chemical structure of the phospholipids and the presence of cholesterol in the membrane.Fatty acids tails of phospholipids can be either saturated or...
01:58Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
01:26Membrane Fluidity
Membrane fluidity is explained by the fluid mosaic model of the cell membrane, which describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character.
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
01:27Synthesis of Phosphatidylcholine in the ER Membrane
The ER synthesizes lipids for building cell membranes and performing cellular functions such as energy storage and signaling. The lipid synthesis machinery embedded in the ER membrane primarily collects all reactants from the cytosol. Following synthesis, the secretory pathway and the ER contact sites distribute these lipids to other cellular organelles. Additionally, the energy-rich triacylglycerides are transported from the ER via lipid droplets.
The major components of all eukaryotic cell...
The major components of all eukaryotic cell...
01:58Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
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...