Kinetics of Tethered Ligands Binding to a Surface Receptor
Kinetics of Tethered Ligands Binding to a Surface Receptor
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DOI：
10.1021/acs.macromol.7b01742
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发表时间：
2017-11-14
期刊：
影响因子：
5.5
通讯作者：
Terentjev, Eugene M.
中科院分区：
文献类型：
--
作者：
Bell, Samuel;Terentjev, Eugene M.
接枝聚合物与表面的结合速率由熵垒控制。使用平均场近似的理想聚合物动力学，我们首先计算的特征结合时间的拴系配体到达位于拴系表面上的结合位点。这个时间是由两个独立的熵效应：一个障碍链被拉伸到足以达到遥远的目标和限制链构象附近的表面，相对于增加可用的相空间较长的链。这两个约束之间的竞争决定了最佳（最短）绑定时间。然后，该理论扩展到两个表面之间的桥接模型，特别是相关的细胞粘附。在这里，束缚的配体到达平行表面上的受体，结合时间取决于两个约束表面之间的差距。再次，针对给定的系绳几何形状确定最佳结合时间。结果看起来类似的自由粒子的“窄逃逸问题”，但修改的熵激活因子引入的系绳。
The rate of binding of a grafted polymer to the surface is controlled by entropic barriers. Using a mean-field approximation of ideal polymer dynamics, we first calculate the characteristic binding time for a tethered ligand reaching for a binding site located on the tethering surface. This time is determined by two separate entropic effects: a barrier for the chain to be stretched sufficiently to reach the distant target and a restriction on chain conformations near the surface, versus the increase in available phase space for longer chains. The competition between these two constraints determines the optimal (shortest) binding time. The theory is then extended to model bridging between two surfaces, in particular relevant for cell adhesion. Here the tethered ligand reaches for a receptor on a parallel surface, and the binding time depends on the gap between the two constraining surfaces. Again, an optimal binding time is determined for the given tether geometry. The results look similar to those for free particles in the "narrow escape problem", but modified by an entropic activation factor introduced by the tether.