Micromolar Ca2+ stimulates fusion of lipid vesicles with planar bilayers containing a calcium-binding protein.
Micromolar Ca2+ stimulates fusion of lipid vesicles with planar bilayers containing a calcium-binding protein.
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微摩尔 Ca2 刺激脂质囊泡与含有钙结合蛋白的平面双层融合。
DOI：
10.1126/science.7434004
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
Finkelstein,A
中科院分区：
文献类型：
--
作者：
Zimmerberg,J;Cohen,FS;Finkelstein,A
磷脂囊泡与含有钙结合蛋白的平面磷脂双层膜的融合似乎模拟了细胞质囊泡与质膜融合（胞吐作用）的基本方面，因为（i）在没有 Ca2++ 的情况下，融合的基础速率较低，（ii）微摩尔（~ 10 μM）量的 Ca2++ 会极大地增加该基础速率，并且（iii）该速率不增加毫摩尔 Mg2+。这个过程的关键是平面膜上的渗透梯度，含有囊泡的一侧相对于另一侧是高渗的。类似的渗透梯度或等价物对于生物融合事件可能至关重要。
Fusion of phospholipid vesicles with a planar phospholipid bilayer membrane that contains a calcium-binding protein appears to mimic the essential aspects of cytoplasmic-vesicle fusion with plasma membranes (exocytosis) in that (i) there is a low basal rate of fusion in the absence of Ca2++, (ii) this basal rate is enormously increased by micromolar (∼ 10 μM) amounts of Ca2++, and (iii) this rate is not increased by millimolar Mg2+. Essential to this process is an osmotic gradient across the planar membrane, with the side containing the vesicles hyperosmotic to the opposite side. Similar osmotic gradients or their equivalent may be crucial for biological fusion events.