Müller M, Katsov K, Schick M
Institute for Physics, Johannes Gutenberg University, Mainz, Germany.
Biophys J. 2003 Sep;85(3):1611-23. doi: 10.1016/S0006-3495(03)74592-5.
We have carried out extensive Monte Carlo simulations of the fusion of tense apposed bilayers formed by amphiphilic molecules within the framework of a coarse-grained lattice model. The fusion pathway differs from the usual stalk mechanism. Stalks do form between the apposed bilayers, but rather than expand radially to form an axial-symmetric hemifusion diaphragm of the trans leaves of both bilayers, they promote in their vicinity the nucleation of small holes in the bilayers. Two subsequent paths are observed. 1) The stalk encircles a hole in one bilayer creating a diaphragm comprised of both leaves of the other intact bilayer, which ruptures to complete the fusion pore. 2) Before the stalk can encircle a hole in one bilayer, a second hole forms in the other bilayer, and the stalk aligns and encircles them both to complete the fusion pore. Both pathways give rise to mixing between the cis and trans leaves of the bilayer and allow for transient leakage.
我们在粗粒化晶格模型的框架内，对两亲分子形成的紧密并置双层膜的融合进行了广泛的蒙特卡罗模拟。融合途径不同于通常的茎状机制。在并置的双层膜之间确实会形成茎，但它们不是径向扩展以形成两个双层膜反式叶的轴对称半融合隔膜，而是在其附近促进双层膜中小孔的成核。观察到两条后续路径。1）茎围绕一个双层膜中的孔，形成一个由另一个完整双层膜的两个叶组成的隔膜，该隔膜破裂以完成融合孔。2）在茎能够围绕一个双层膜中的孔之前，另一个双层膜中形成第二个孔，并且茎对齐并围绕它们两者以完成融合孔。两条途径都会导致双层膜顺式叶和反式叶之间的混合，并允许瞬时泄漏。
