论文标题
载荷下的细丝运动蛋白系统：不稳定性和限制周期振荡
Filament-motor protein system under loading: instability and limit cycle oscillations
论文作者
论文摘要
我们考虑在外部负载下的运动蛋白测定中刚性细丝的动力学。运动蛋白被建模为具有固定在基板上的尾端的主动谐波接头。它们的头部随机伸到灯丝上，以沿其延伸，从而在脱落前会导致灯丝的力。扩展和脱离的速度取决于负载。在这里，我们使用线性稳定性分析以及运动蛋白和细丝的直接数值模拟在平均场近似中制定并表征了控制动力学。在恒定载荷下，系统显示从稳定的构型到不稳定的过渡到丝从运动蛋白脱离。在弹性载荷下，我们发现稳定的极限周期振荡通过超临界的霍夫夫分叉，活动变化和运动蛋白的数量。系统的数值模拟大量运动蛋白与平均场预测非常吻合。
We consider the dynamics of a rigid filament in a motor protein assay under external loading. The motor proteins are modeled as active harmonic linkers with tail ends immobilized on a substrate. Their heads attach to the filament stochastically to extend along it, resulting in a force on the filament, before detaching. The rate of extension and detachment are load dependent. Here we formulate and characterize the governing dynamics in the mean field approximation using linear stability analysis, and direct numerical simulations of the motor proteins and filament. Under constant loading, the system shows transition from a stable configuration to instability towards detachment of the filament from motor proteins. Under elastic loading, we find emergence of stable limit cycle oscillations via a supercritical Hopf bifurcation with change in activity and the number of motor proteins. Numerical simulations of the system for large number of motor proteins show good agreement with the mean field predictions.
