Electron microscopic analysis of lipid clusters and membrane proteins in plasma membrane.

我们使用最近开发的选择性结合特定脂质或脂质团的肽/蛋白检查了质膜中的跨双分子层和侧向脂质分布。脂质体实验表明，即使膜浓度低至1 mol%，探针也能有效检测到脂质，并且探针与模拟小叶内外脂质环境的模型膜结合相似。接下来，我们检查了鞘磷脂和磷脂酰丝氨酸在静息血小板和凝血酶刺激血小板以及具有高度促凝作用的血小板微粒中的分布。我们的研究结果表明，在凝血酶激活的血小板中，混乱的膜以微粒的形式选择性地释放出来，并提出了内部小叶中的磷脂酰丝氨酸暴露于外部触发血小板囊泡的想法。

We examined transbilayer and lateral lipid distribution in plasma membrane using recently developed peptide/proteins that selectively bind specific lipids or lipid clusters. The liposome experiments demonstrated that the lipids were effectively detected by the probes even when the membrane concentration was as low as 1 mol%, and the probes bound similarly to the model membranes that mimic outer or inner leaflet lipid environment.Next, we examined the distribution of sphingomyelin and phosphatidylserine in resting and thrombin-stimulated platelets as well as platelet microparticles that are highly procoagulant. Our results indicate that the scrambled membranes are selectively released in the form of microparticles in thrombin-activated platelets and suggest the idea that the exposure of phosphatidylserine in inner leaflet to the outer triggers the vesiculation of platelets.