High-resolution mapping of phase behavior in a ternary lipid mixture: Do lipid-raft phase boundaries depend on the, sample preparation procedure?
High-resolution mapping of phase behavior in a ternary lipid mixture: Do lipid-raft phase boundaries depend on the, sample preparation procedure?
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DOI：
10.1021/la702490r
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发表时间：
2007-11-20
期刊：
影响因子：
3.9
通讯作者：
Schutzer, Matthew
中科院分区：
文献类型：
--
作者：
Buboltz, Jeffrey T.;Bwalya, Charles;Schutzer, Matthew
一段时间以来，我们一直在使用荧光共振能量转移（FRET）为基础的战略进行高分辨率的研究相行为在三元脂筏膜混合物。我们的FRET实验可以在普通的多分散多层囊泡悬浮液上进行，因此我们能够根据专门设计用于防止人为相分离的程序制备样品。在某些方面（即，观察到的两相区的数量和性质），我们的相图与以前发表的报告中的相图是一致的。然而，在其他方面（即，可渗透性间隙的总体尺寸、相边界位置及其对温度的依赖性），存在明显的差异。在这里，我们提出的FRET数据在二油酰磷脂酰胆碱/二棕榈酰磷脂酰胆碱/胆固醇（DOPC/DPPC/胆固醇）的混合物在25.0，35.0和45.0摄氏度。我们的研究结果和以前报道的相界之间的比较表明，脂筏混合物可能是特别容易在样品制备过程中的分层效应。
For some time now, we have been using a fluorescence resonance energy transfer (FRET)-based strategy to conduct high-resolution studies of phase behavior in ternary lipid-raft membrane mixtures. Our FRET experiments can be carried out on ordinary, polydisperse multilamellar vesicle suspensions, so we are able to prepare our samples according to a procedure that was designed specifically to guard against artifactual phase separation. In some respects (i.e., the number and nature of two-phase regions observed), our phase diagrams are consistent with those in previously published reports. However, in other respects (i.e., overall size of miscibility gaps, phase boundary locations and their dependence on temperature), there are clear differences. Here, we present FRET data taken in dioleoylphosphatidylcholine/ dipalmitoylphosphatidylcholine/cholesterol (DOPC/DPPC/Chol) mixtures at 25.0, 35.0, and 45.0 degrees C. Comparisons between our results and previously reported phase boundaries suggest that lipid-raft mixtures may be particularly susceptible to demixing effects during sample preparation.