DETAILED MECHANICS OF MEMBRANE-MEMBRANE ADHESION AND SEPARATION .2. DISCRETE KINETICALLY TRAPPED MOLECULAR CROSS-BRIDGES
DETAILED MECHANICS OF MEMBRANE-MEMBRANE ADHESION AND SEPARATION .2. DISCRETE KINETICALLY TRAPPED MOLECULAR CROSS-BRIDGES
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DOI：
10.1016/s0006-3495(85)83771-1
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发表时间：
1985-01-01
影响因子：
3.4
通讯作者：
EVANS, EA
中科院分区：
文献类型：
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作者：
EVANS, EA
一般来说，膜-膜粘附涉及特异性分子结合和交联反应。理想的、经典的观点是，接近平衡时，分离粘合剂接触所需的力基本上等于形成接触时在膜中引起的力。与经典观点相反，实验观察经常表明，即使分离接触所需的张力大到足以使膜破裂，粘合剂接触引起的张力水平也可以忽略不计。与接触形成和分离相关的张力水平的偏差似乎是由于强分子交叉桥的稀疏分布。在这里，膜-膜粘附和分离的力学是针对离散的、动力学上被捕获的横桥的情况开发的。该解是通过对接触区总自由能（变形的膜弹性能加上跨桥能量）最小化的膜轮廓进行数值计算获得的。该解与相邻非桥接区的膜应力和几何形状的解析解相匹配。结果产生的宏观张力施加到膜的平面区域远离接触区和接触区的边缘处的微观角度的具体值。发现两个不同的宏观张力值：分离粘附膜所需的最小张力;以及当形成接触时在膜中引起的最大张力（即，接触将开始蔓延的张力水平）。结果表明，这两个张力之间的偏差可以是很大的，强烈地依赖于跨桥的表面密度。此外，结果提供了一个估计的约束力，锚受体的平面内的膜。
In general, membrane-membrane adhesion involves specific molecular binding and cross-bridging reactions. The ideal, classical view is that near equilibrium the forces required to separate adhesive contacts are essentially equal to those induced in the membrane when the contact is formed. In contrast to the classical view, experimental observations often show that negligible levels of tension are induced by the adhesive contact even though the tension required to separate the contact is large enough to rupture the membrane. The deviation in tension levels associated with contact formation and separation appears to be due to the sparse distribution of strong molecular cross-bridges. Here, the mechanics of membrane-membrane adhesion and separation is developed for the case of discrete, kinetically trapped cross-bridges. The solution is obtained by numerical computation of the membrane contour that minimizes the total free energy (membrane elastic energy of deformation plus cross-bridge energies) in the contact zone. This solution is matched with the analytical solution for membrane stresses and geometry derived for the adjacent, unbridged zone. The results yield specific values of the macroscopic tension applied to the membrane in the plane region away from the contact zone and the microscopic angle at the edge of the contact zone. Two disparate values of the macroscopic tension are found: the minimum tension required to separate the adherent membranes; and the maximum tension induced in the membranes when the contact is formed (i.e., the level of tension at which the contact will just begin to spread). The results show that the deviation between these 2 tensions can be very large and depends strongly on the surface density of cross-bridges. In addition, the results provide an estimation of the restraining forces that anchor receptors within the plane of the membrane.