标题： 限制与活性驱动的半柔性聚合物在运动分析中的动力学 显示英文标题

标题： Confinement and Activity-Driven Dynamics of Semiflexible Polymers in Motility Assays

摘要： 我们研究了在运动检测实验中半刚性聚合物的动力学，其中马达蛋白（MPs）在谐波限制的影响下随机地结合、解离并沿聚合物移动。 使用朗之万动力学模拟，我们探讨了聚合物的刚度、马达蛋白的附着/解离及随后的移动所带来的活性，以及陷阱强度之间的相互作用，揭示了从被束缚到自由聚合物的两态转变，中间存在共存区域。 刚度显著影响束缚行为，柔性聚合物在高活性下仍保持被束缚状态。 马达蛋白的附着/解离也可以改变聚合物的有效刚度，从而影响陷阱的束缚。聚合物经历螺旋和开链构象，扭转数作为量化螺旋形成的键序参数。 我们表明，束缚稳定了螺旋结构并抑制了开链运动，尤其是在高活性下。 通过均方位移（MSD）分析质心（COM）动力学，显示出扩散、弹道和扩散区域，这些区域取决于陷阱强度和活性。 负超额峰度表明非平衡行为，并随着束缚增强而饱和，反映了陷阱对活性的主导作用。 显示英文摘要

摘要： We investigate the dynamics of semiflexible polymers in a motility assay, where motor proteins (MPs) stochastically bind, unbind, and walk along the polymer, under the influence of harmonic confinement. Using Langevin dynamics simulations, we explore the interplay between the polymer's rigidity, activity in the form of attachment/detachment of MPs and subsequent movement of attached MPs, and trap strength, revealing a two-state transition from a trapped to a free polymer, with an intermediate coexistence region. Rigidity significantly impacts the trapping behaviour, with flexible polymers remaining trapped at the higher activity. Attachment/detachment of MPs can also induce a change in the effective rigidity of the polymer and, therefore, influence confinement by the trap.The polymer undergoes spiral and open-chain conformations, with the turning number serving as a key order parameter to quantify spiral formation. We show that confinement stabilizes spiral structures and suppresses open-chain motion, especially at higher activity. The centre of mass (COM) dynamics are analyzed through the mean square displacement (MSD), showing diffusive, ballistic, and diffusive regimes that depend on the trap strength and activity. Negative excess kurtosis indicates nonequilibrium behaviour, which saturates with increasing confinement, reflecting the dominance of the trap over the activity.