Vesicle propulsion in haptotaxis: A local model
Vesicle propulsion in haptotaxis: A local model
复制标题
趋触性中的囊泡推进：局部模型
DOI：
10.1007/s101890070011
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Y. Saito
中科院分区：
文献类型：
--
作者：
I. Cantat;C. Misbah;Y. Saito
我们从理论上研究由于haptotaxis囊泡运动。趋触性是指由基底上的粘附梯度引起的运动。该问题是在一个局部近似的瑞利型耗散是通过解决。动力学模型类似于聚合物的非线性模型。一个不变的配方是用来解决的动力学模型，其中包括一种耗散由于键断裂/恢复与基板。对于一个固定的情况下，囊泡获得一个恒定的漂移速度，我们制定的推进问题的非线性特征值（thea prioriunknown漂移速度）的Barenblat-Zeldovitch型之一。一个计数的论点表明，速度属于一个离散集。对于一个相对紧张的囊泡，我们提供了一个解析表达式的漂移速度作为相关参数的函数。我们发现与完整的数值解很好的协议。尽管模型过于简化，它允许识别相关的量，即粘附长度，这在存在流体动力学的非局部模型中也是至关重要的，我们最近报道了这种情况（I. Cantat和C. Misbah，Phys.Rev.Lett.83，235（1999）），并且其构成了即将进行的广泛研究的主题。
We study theoretically vesicle locomotion due to haptotaxis. Haptotaxis is referred to motion induced by an adhesion gradient on a substrate. The problem is solved within a local approximation where a Rayleigh-type dissipation is adopted. The dynamical model is akin to the Rousse model for polymers. An invariant formulation is used to solve a dynamical model which includes a kind of dissipation due to bond breaking/restoring with the substrate. For a stationary situation where the vesicle acquires a constant drift velocity, we formulate the propulsion problem in terms of a nonlinear eigenvalue (thea prioriunknown drift velocity) one of Barenblat-Zeldovitch type. A counting argument shows that the velocity belongs to a discrete set. For a relatively tense vesicle, we provide an analytical expression for the drift velocity as a function of relevant parameters. We find good agreement with the full numerical solution. Despite the oversimplification of the model it allows the identification of a relevant quantity, namely the adhesion length, which turns out to be crucial also in the nonlocal model in the presence of hydrodynamics, a situation on which we have recently reported (I. Cantat and C. Misbah, Phys. Rev. Lett.83, 235 (1999)) and which constitutes the subject of a forthcoming extensive study.