胆固醇对和和不和脂混合能力的影响的原子模拟:对液体有序/液体无序相共存的影响
Jason de Joannis1, Patrick S Coppock, Fuchang Yin
1Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States.
Journal of the American Chemical Society
|February 24, 2011
概括
这项研究使用分子动力学/蒙特卡洛模拟来研究脂质-活体相互作用. 结果显示,胆固醇首选与DPPC脂质相关,影响双层阶段行为和脂质排序.
科学领域:
- 生物物理学的生物物理.
- 计算化学计算化学
- 材料科学 材料科学 材料科学
背景情况:
- 了解脂质-活体相互作用对于细胞膜研究至关重要.
- 胆固醇显著调节膜特性和相位行为.
- 分子模拟提供了一个强大的工具,以探测这些复杂的相互作用在原子层面.
研究的目的:
- 通过计算来确定DPPC和DOPC脂质对于富含胆固醇的环境的相对亲和力.
- 对实验阶段行为数据进行原子模拟模型的验证.
- 阐明脂质 - 胆固醇合作性背后的分子机制.
主要方法:
- 使用混合分子动力学/蒙特卡洛 (MD/MC) 模拟.
- 使用脂类之间化学潜能 (Δμ) 的固定差异.
- 在不同的胆固醇度中分析了三元DPPC/DOPC/胆固醇二层.
主要成果:
- 随着胆固醇含量增加,DPPC/DOPC比率增加,这表明DPPC在有序域中的丰富.
- 模拟准确地复制了脂质-活体化合物的实验趋势.
- 在富含DOPC的地区,DPPC/DOPC的比例显示对胆固醇的依赖程度在16%以下,这表明DPPC与胆固醇的相互作用是合作的.
- 胆固醇与双层正常调整影响了脂质亲和力,与观察到的合作性相关.
结论:
- 固定 Δμ 的 MD/MC 模拟有效地预测了相对的脂质亲和力和双层相位行为.
- DPPC和胆固醇表现出合作相互作用,导致它们在特定的膜领域的共同丰富.
- 胆固醇在双层中的分子定位是推动这些成分依赖相互作用的关键因素.
相关概念视频
Membrane 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...
Membrane 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...
Fluid 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...
Fluid Mosaic Model
The fluid mosaic model was first proposed as a visual representation of research observations. The model comprises the composition and dynamics of membranes and serves as a foundation for future membrane-related studies. The model depicts the structure of the plasma membrane with a variety of components, which include phospholipids, proteins, and carbohydrates. These integral molecules are loosely bound, defining the cell’s border and providing fluidity for optimal function.LipidsThe most...
Asymmetric Lipid Bilayer
Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...
What are Lipids?
Overview


