疏水力,静电转向和原子光滑的自组装单层和终端功能化的PEGolated脂质双层之间的酸桥梁
Markus Valtiner1, Stephen H Donaldson, Matthew A Gebbie
1Department of Chemical Engineering, University of California Santa Barbara (UCSB), Santa Barbara, California 93106-5080, USA.
Journal of the American Chemical Society
|December 20, 2011
概括
了解表面之间的分子相互作用对于开发智能材料至关重要. 这项研究量化了聚合物涂层表面之间的力,揭示了先进应用的pH依赖的结合机制.
科学领域:
- 表面科学是一门科学.
- 聚合物化学 聚合物化学
- 生物物理学的生物物理.
背景情况:
- 接口上的分子相互作用决定了智能表面的功能.
- 了解这些力量对于生物,医学和材料科学应用至关重要.
- 终端功能化聚合物在设计这些表面方面发挥着关键作用.
研究的目的:
- 量化分析不对称表面之间的相互作用力和结合动力学.
- 为了将这些力量与化学结构和分子设计相关联.
- 研究pH在控制这些相互作用中的作用.
主要方法:
- 开发了一种新的表面力装置实验.
- 在金基板上使用自组装单层 (SAM),具有不同的头组功能 (碳酸,酒精,甲基).
- 在脂质双层上研究了与氨酸末端功能化聚乙烯糖醇 (PEG) 聚合物的相互作用.
主要成果:
- 量化特定的酸结合,PEG链的固体效应和疏水粘附.
- 证明了pH取决于对相互作用力的控制.
- 确定了碳酸和氨基团之间的快速,电荷介导的键.
结论:
- 反电荷组之间的特定,pH值依赖的结合促进了快速和强烈的相互作用.
- 静电方向盘甚至在聚合物链延伸时也会影响结合概率.
- 这些发现对蛋白质折叠和酶催化有影响.
相关概念视频
Micelles
Micelle formation is an intricate process that hinges on the properties of amphiphilic or amphipathic molecules and the conditions of the system in which they are found. Amphiphilic molecules, which have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts, play a critical role in this process.In aqueous environments, these molecules arrange themselves such that their hydrophilic heads are turned towards the water phase, while their hydrophobic tails are oriented away...
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%...
Surface Active Agents
Surfactants, named for their behavior at interfaces, positively adsorb at the interfaces of two phases, reducing interfacial tension. Their versatility as emulsifiers, detergents, and foaming agents stems from this ability. Surfactants, often termed amphiphiles, share the property of amphipathy, with molecules having both hydrophilic and hydrophobic portions. The hydrophilic part is called the head, and the hydrophobic part, including an elongated alkyl substituent, forms the tail.Surfactants...
Lipids as Anchors
In the plasma membrane, the lipids forming the bilayer can also act as an anchor to tether proteins to the membrane. The three main types of lipid anchors found in eukaryotes are – prenyl groups, fatty acyl groups, and glycosylphosphatidylinositol or GPI groups. Prenyl and fatty acyl groups act as anchors on the cytosolic surface of the membrane, whereas GPI anchors proteins on the extracellular side.
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
Mechanisms 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...
The 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.


