Department of Materials Science and Engineering, National University of Singapore, Singapore.
J R Soc Interface. 2012 May 7;9(70):928-37. doi: 10.1098/rsif.2011.0553. Epub 2011 Sep 21.
Under increasing tensile load, the lifetime of a single catch bond counterintuitively increases up to a maximum and then decreases exponentially like a slip bond. So far, the characteristics of single catch bond dissociation have been extensively studied. However, it remains unclear how a cluster of catch bonds behaves under tensile load. We perform computational analysis on the following models to examine the characteristics of clustered catch bonds: (i) clusters of catch bonds with equal load sharing, (ii) clusters of catch bonds with linear load sharing, and (iii) clusters of catch bonds in micropipette-manipulated cell detachment. We focus on the differences between the slip and catch bond clusters, identifying the critical factors for exhibiting the characteristics of catch bond mechanism for the multiple-bond system. Our computation reveals that for a multiple-bond cluster, the catch bond behaviour could only manifest itself under relatively uniform loading conditions and at certain stages of decohesion, explaining the difficulties in observing the catch bond mechanism under real biological conditions.
在持续增加的张力负载下，单捕获键的寿命反直觉地先增加到最大值，然后像滑动键一样呈指数下降。到目前为止，已经广泛研究了单捕获键解离的特性。然而，在张力负载下，一群捕获键的行为如何仍不清楚。我们对以下模型进行了计算分析，以检查聚集捕获键的特性：（i）具有相等负载分配的捕获键簇，（ii）具有线性负载分配的捕获键簇，以及（iii）微管操纵细胞脱离中的捕获键簇。我们专注于滑动键簇和捕获键簇之间的差异，确定在多键系统中表现出捕获键机制特性的关键因素。我们的计算表明，对于多键簇，只有在相对均匀的加载条件下，并且在脱附和的某些阶段，捕获键行为才能表现出来，这解释了在实际生物条件下观察捕获键机制的困难。
