Marsh Derek
Max-Planck-Institut für biophysikalische Chemie, Abteilung Spektroskopie und photochemische Kinetik, 37070 Göttingen, Germany.
Biochim Biophys Acta. 2009 Oct;1788(10):2114-23. doi: 10.1016/j.bbamem.2009.08.004. Epub 2009 Aug 21.
The biophysical underpinning of the lipid-raft concept in cellular membranes is the liquid-ordered phase that is induced by moderately high concentrations of cholesterol. Although the crucial feature is the coexistence of phase-separated fluid domains, direct evidence for this in mixtures of cholesterol with a single lipid is extremely sparse. More extensive evidence comes from ternary mixtures of a high chain-melting lipid and a low chain-melting lipid with cholesterol, including those containing sphingomyelin that are taken to be a raft paradigm. There is, however, not complete agreement between the various phase diagrams and their interpretation. In this review, the different ternary phase diagrams of cholesterol-containing systems are presented in a uniform way, using simple x,y-coordinates to increase accessibility for the non-specialist. It is then possible to appreciate the common features and examine critically the discrepancies and hence what direct biophysical evidence there is that supports the raft concept.
细胞膜中脂筏概念的生物物理基础是由适度高浓度胆固醇诱导产生的液晶相。尽管关键特征是相分离流体域的共存，但胆固醇与单一脂质混合物中关于此的直接证据极为稀少。更广泛的证据来自高链熔点脂质、低链熔点脂质与胆固醇的三元混合物，包括那些含有鞘磷脂的混合物，它们被视为脂筏范例。然而，不同的相图及其解释之间并未完全达成一致。在本综述中，使用简单的x,y坐标以统一的方式呈现含胆固醇体系的不同三元相图，以便非专业人士更易理解。这样就有可能认识到共同特征，并批判性地审视差异，进而审视支持脂筏概念的直接生物物理证据。
