Zimmerberg J, Cohen F S, Finkelstein A
Science. 1980 Nov 21;210(4472):906-8. doi: 10.1126/science.7434004.
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 (approximately 10 microM) 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.
含有钙结合蛋白的磷脂囊泡与平面磷脂双分子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，即：（i）在没有Ca2+的情况下融合的基础速率较低；（ii）微摩尔（约10 microM）量的Ca2+可极大地提高该基础速率；（iii）毫摩尔的Mg2+不会提高该速率。此过程的关键是跨平面膜的渗透梯度，含有囊泡的一侧相对于另一侧为高渗。类似的渗透梯度或其等效物可能对生物融合事件至关重要。
