THE REACTION-LIMITED KINETICS OF MEMBRANE-TO-SURFACE ADHESION AND DETACHMENT
THE REACTION-LIMITED KINETICS OF MEMBRANE-TO-SURFACE ADHESION AND DETACHMENT
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DOI：
10.1098/rspb.1988.0038
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发表时间：
1988-06-22
期刊：
影响因子：
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通讯作者：
HAMMER, D
中科院分区：
文献类型：
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作者：
DEMBO, M;TORNEY, DC;HAMMER, D
生物粘附通常由特定的膜蛋白（粘附分子）介导。从粘附分子的概念开始，我们提出了一个简单的模型的物理膜表面附着和分离。该模型包括耦合方程的弹性膜的变形与方程的化学动力学的粘附分子。我们提出了一套本构关系的键应力，键应变和化学速率常数的粘附分子键应变。我们导出了临界张力的精确公式。我们还描述了一个快速，准确的有限差分算法生成我们的模型的数值解。使用该算法，我们能够计算的瞬态行为在初始阶段的粘附和分离，以及稳态的几何形状的粘附和接触的速度。我们的模型的一个意想不到的结果是预测发生的状态，其中粘附力不能通过施加张力逆转。只有当粘附分子具有某些组成性质（捕获键）时，才会发生这种状态。我们讨论了这种捕获键的合理性及其可能的生物学意义。最后，通过对数值解的分析，我们得到了一个精确的和一般的稳态附着和脱离速度的表达式。作为该理论的应用，我们讨论了粒细胞在毛细血管后微静脉中的滚动速度和凝集素介导的红细胞粘附的数据。
Biological adhesion is frequently mediated by specific membrane proteins (adhesion molecules). Starting with the notion of adhesion molecules, we present a simple model of the physics of membrane-to-surface attachment and detachment. This model consists of coupling the equations for deformation of an elastic membrane with equations for the chemical kinetics of the adhesion molecules. We propose a set of constitutive laws relating bond stress to bond strain and also relating the chemical rate constants of the adhesion molecules to bond strain. We derive an exact formula for the critical tension. We also describe a fast and accurate finite difference algorithm for generating numerical solutions of our model. Using this algorithm, we are able to compute the transient behaviour during the initial phases of adhesion and detachment as well as the steady-state geometry of adhesion and the velocity of the contact. An unexpected consequence of our model is the predicted occurrence of states in which adhesion cannot be reversed by application of tension. Such states occur only if the adhesion molecules have certain constitutive properties (catch-bonds). We discuss the rational for such catch-bonds and their possible biological significance. Finally, by analysis of numerical solutions, we derive an accurate and general expression for the steady-state velocity of attachment and detachment. As applications of the theory, we discuss data on the rolling velocity of granulocytes in post-capillary venules and data on lectin-mediated adhesion of red cells.