Dieterle Paul B, Zheng Jenny, Garner Ethan, Amir Ariel
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev E. 2022 Jun;105(6-1):064503. doi: 10.1103/PhysRevE.105.064503.
Dynamic instability-the growth, catastrophe, and shrinkage of quasi-one-dimensional filaments-has been observed in multiple biopolymers. Scientists have long understood the catastrophic cessation of growth and subsequent depolymerization as arising from the interplay of hydrolysis and polymerization at the tip of the polymer. Here we show that for a broad class of catastrophe models, the expected catastrophe time distribution is exponential. We show that the distribution shape is insensitive to noise, but that depletion of monomers from a finite pool can dramatically change the distribution shape by reducing the polymerization rate. We derive a form for this finite-pool catastrophe time distribution and show that finite-pool effects can be important even when the depletion of monomers does not greatly alter the polymerization rate.
动态不稳定性——准一维细丝的生长、灾变和收缩——已在多种生物聚合物中被观察到。长期以来，科学家们一直认为聚合物末端水解和聚合作用的相互影响导致了生长的灾难性停止以及随后的解聚。在这里，我们表明，对于一大类灾变模型，预期的灾变时间分布是指数型的。我们表明，分布形状对噪声不敏感，但有限单体库中单体的消耗会通过降低聚合速率而显著改变分布形状。我们推导了这种有限单体库灾变时间分布的形式，并表明即使单体消耗并没有极大地改变聚合速率，有限单体库效应也可能很重要。
