Veatch Sarah L, Keller Sarah L
Department of Physics, University of Washington, Seattle WA 98195, USA.
Biochim Biophys Acta. 2005 Dec 30;1746(3):172-85. doi: 10.1016/j.bbamcr.2005.06.010. Epub 2005 Jul 6.
Liquid domains in model lipid bilayers are frequently studied as models of raft domains in cell plasma membranes. Micron-scale liquid domains are easily produced in vesicles composed of ternary mixtures of a high melting temperature lipid, a low melting temperature lipid, and cholesterol. Here, we describe the rich phase behavior observed in binary and ternary systems. We then discuss experimental challenges inherent in mapping phase diagrams of even simple lipid systems. For example, miscibility behavior varies with lipid type, lipid ratio, lipid oxidation, and level of impurity. Liquid domains are often circular, but can become noncircular when membranes are near critical points. Finally, we reflect on applications of phase diagrams in model systems to rafts in cell membranes.
模型脂双层中的液相区域常被作为细胞质膜中筏结构域的模型进行研究。在由高熔点脂质、低熔点脂质和胆固醇的三元混合物组成的囊泡中，很容易产生微米级的液相区域。在此，我们描述了在二元和三元系统中观察到的丰富相行为。然后，我们讨论了绘制即使是简单脂质系统的相图所固有的实验挑战。例如，混溶行为会随脂质类型、脂质比例、脂质氧化和杂质水平而变化。液相区域通常是圆形的，但当膜接近临界点时会变成非圆形。最后，我们思考了模型系统中的相图在细胞膜筏结构方面的应用。
