Zhang F, Lee G M, Jacobson K
Department of Cell Biology and Anatomy, University of North Carolina at Chapel Hill 27599-7090.
Bioessays. 1993 Sep;15(9):579-88. doi: 10.1002/bies.950150903.
The lateral mobility of membrane lipids and proteins is presumed to play an important functional role in biomembranes. Photobleaching studies have shown that many proteins in the plasma membrane have diffusion coefficients at least an order of magnitude lower than those obtained when the same proteins are reconstituted in artificial bilayer membranes. Depending on the protein, it has been shown that either the cytoplasmic domain or the ectodomain is the key determinant of its lateral mobility. Single particle tracking microscopy, which allows the motions of single or small groups of membrane molecules to be followed, promises not only to reveal new features of membrane dynamics, but also to help explain longstanding puzzles presented by the photobleaching studies, particularly the so-called immobile fraction. The combination of the two complementary technologies should measurably enhance our understanding of membrane microstructure.
膜脂和膜蛋白的侧向流动性被认为在生物膜中发挥着重要的功能作用。光漂白研究表明，质膜中的许多蛋白质的扩散系数比在人工双层膜中重组相同蛋白质时获得的扩散系数至少低一个数量级。根据蛋白质的不同，已表明胞质结构域或胞外结构域是其侧向流动性的关键决定因素。单粒子追踪显微镜能够追踪单个或小群膜分子的运动，不仅有望揭示膜动力学的新特征，还能帮助解释光漂白研究提出的长期难题，特别是所谓的固定组分。这两种互补技术的结合应能显著增强我们对膜微观结构的理解。
