标题： 肌动蛋白丝和微管生长是反应限制还是扩散限制？ 显示英文标题

标题： Is Actin Filament and Microtubule Growth Reaction- or Diffusion-Limited?

摘要： 在活体生物细胞内，肌动蛋白丝和微管通过从细胞质中摄取肌动蛋白或微管蛋白而动态地自我组装和解聚，或将它们释放到其尖端的周围环境。 这种反应-扩散系统可以表现出扩散限制或反应限制的行为。 然而，这两种极限都无法解释实验数据：虽然生长速度与整体微管蛋白密度之间的线性关系的偏移与扩散极限相矛盾，但生长速度的出人意料的大方差则拒绝了纯粹的反应极限。 在本信中，我们同时考虑了这两种极限，并使用Doi-Peliti场论模型来估计扩散传输如何干扰丝状物尖端的化学反应。 此外，预测了一个交叉的整体密度，在该密度下，限制过程从化学反应转变为扩散传输。 此外，我们解释并估算了生长速度更大的方差。 显示英文摘要

摘要： Inside cells of living organisms, actin filaments and microtubules self-assemble and dissemble dynamically by incorporating actin or tubulin from the cell plasma or releasing it into their tips' surroundings. Such reaction-diffusion systems can show diffusion- or reaction-limited behaviour. However, neither limit explains the experimental data: while the offset of the linear relation between growth speed and bulk tubulin density contradicts the diffusion limit, the surprisingly large variance of the growth speed rejects a pure reaction limit. In this Letter, we accommodate both limits and use a Doi-Peliti field-theory model to estimate how diffusive transport is perturbing the chemical reactions at the filament tip. Furthermore, a crossover bulk density is predicted at which the limiting process changes from chemical reactions to diffusive transport. In addition, we explain and estimate larger variances of the growth speed.