A raft-associated species of phosphatidylethanolamine interacts with cholesterol comparably to sphingomyelin. A Langmuir-Blodgett monolayer study.
A raft-associated species of phosphatidylethanolamine interacts with cholesterol comparably to sphingomyelin. A Langmuir-Blodgett monolayer study.
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DOI：
10.1371/journal.pone.0005053
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发表时间：
2009
期刊：
影响因子：
3.7
通讯作者：
Sikorski AF
中科院分区：
文献类型：
--
作者：
Grzybek M;Kubiak J;Łach A;Przybyło M;Sikorski AF
鞘磷脂（SM）和胆固醇（Ch）之间的特异性相互作用通常被认为在生物膜中筏的形成中起关键作用。该模型的一个弱点是暗示这些微域局限于外层双分子层小叶。含有大量磷脂酰乙醇胺（PE）、磷脂酰丝氨酸（PS）和磷脂酰肌醇（PI）的细胞质小叶也被认为含有一半的膜胆固醇。此外，SLPE（1-硬脂酰-2-亚油酰-sn-甘油-3-磷脂酰-乙醇胺）最近被证明在分离的耐洗涤剂膜（DRM）中富集，并且这种富集与DRM的分离方法无关。在这里，我们提供了来自Langmuir-Blodgett单层实验的定量证据，证明SLPE与Ch形成的络合物类似于SM与Ch之间的络合物。单层研究计算出的这些相互作用的能量是高度负的。FRAP分析显示，在DOPC/Ch SM或SLPE组成的脂质体中，NBD-Ch的回收率相似，而DPPE则不同，这进一步证明了SLPE可能在高Ch浓度下形成低相。对含DPPE/Ch（1∶1）、SM/Ch（1∶1）和SLPE/Ch（1∶1）的DOPC脂质体的溶解度进行了实验，发现SM/Ch和SLPE/Ch的DOPC脂质体中存在Triton X-100不溶性浮粒（TIFF），而含DPPE/Ch的DOPC脂质体中不存在TIFF。定量测定TIFF部分中特定的脂质种类证实了SLPE（或类似的PE种类）可能是内小叶筏的重要组成部分的结论。这种相互作用表明可能存在由胆固醇复合物与SLPE或类似的不饱和PE组成的内叶纳米级组件。
Specific interactions between sphingomyelin (SM) and cholesterol (Ch) are commonly believed to play a key role in the formation of rafts in the biological membranes. A weakness of this model is the implication that these microdomains are confined to the outer bilayer leaflet. The cytoplasmic leaflet, which contains the bulk of phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI), is thought also to harbour half of the membrane cholesterol. Moreover, SLPE (1-stearoyl-2-linoleoyl-sn-glycero-3-phosphatidyl-ethanolamine) has recently been shown to be enriched in isolated detergent-resistant membranes (DRM), and this enrichment was independent of the method of isolation of DRM. Here we present quantitative evidence coming from Langmuir-Blodgett monolayer experiments that SLPE forms complex with Ch similar to that between SM and Ch. The energies of these interactions as calculated form the monolayer studies are highly negative. FRAP analysis showed that NBD-Ch recovery was similar in liposomes composed of DOPC/Ch SM or SLPE but not DPPE, providing further evidence that SLPE may form an lo phase in the presence of high Ch concentration. Experiments on the solubility of DOPC liposomes containing DPPE/Ch (1∶1), SM/Ch (1∶1) or SLPE/Ch (1∶1) showed the presence of Triton X-100 insoluble floating fraction (TIFF) in the case of SM/Ch or SLPE/Ch but not in DPPE/Ch containing liposomes. Quantitative determination of particular lipid species in the TIFF fraction confirms the conclusion that SLPE (or similar PE species) could be an important constituent of the inner leaflet raft. Such interactions suggest a possible existence of inner-leaflet nanoscale assemblies composed of cholesterol complexes with SLPE or similar unsaturated PE species.
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影响因子：
3.4
作者：
Li, XM;Momsen, MM;Brown, RE
通讯作者：
Brown, RE
DOI：
10.1016/j.colsurfa.2005.12.044
发表时间：
2006-07-20
影响因子：
5.2
作者：
Coste, Virginie;Breton, Michelyne;Puff, Nicolas
通讯作者：
Puff, Nicolas
影响因子：
3.4
作者：
Dietrich, C;Bagatolli, LA;Gratton, E
通讯作者：
Gratton, E
DOI：
10.1073/pnas.0511136103
发表时间：
2006-02-21
影响因子：
11.1
作者：
Brügger, B;Glass, B;Kräusslich, HG
通讯作者：
Kräusslich, HG
影响因子：
5.8
作者：
Dynarowicz-Latka, P;Hac-Wydro, K
通讯作者：
Hac-Wydro, K