PDF(Pubmed)
Abstract：
Studies of biological membrane heterogeneity particularly benefit from the use of the environment-sensitive fluorescent probe Laurdan, for which shifts in the emission, produced by any stimulus (e.g., fluidity variations), are ascribed to alterations in hydration near the fluorophore. Ironically, no direct measure of the influence of the membrane hydration level on Laurdan spectra has been available. To address this, we investigated the fluorescence spectrum of Laurdan embedded in solid-supported lipid bilayers as a function of hydration and compared it with the effect of cholesterol─a major membrane fluidity regulator. The effects are illusively similar, and hence the results obtained with this probe should be interpreted with caution. The dominant phenomenon governing the changes in the spectrum is the hindrance of the lipid internal dynamics. Furthermore, we unveiled the intriguing mechanism of dehydration-induced redistribution of cholesterol between domains in the phase-separated membrane, which reflects yet another regulatory function of cholesterol.
摘要：
生物膜异质性的研究特别受益于使用环境敏感的荧光探针Laurdan，排放的变化，由任何刺激产生(例如，流动性变化)，归因于荧光团附近水合作用的改变。讽刺的是,没有直接测量膜水合水平对Laurdan光谱的影响。为了解决这个问题，我们研究了包埋在固体支持的脂质双层中的Laurdan的荧光光谱与水合作用的关系，并将其与主要的膜流动性调节剂胆固醇的作用进行了比较。效果非常相似，因此，使用该探针获得的结果应谨慎解释。控制光谱变化的主要现象是脂质内部动力学的阻碍。此外，我们揭示了脱水诱导的胆固醇在相分离膜中结构域之间重新分布的有趣机制，这反映了胆固醇的另一种调节功能。
