Diffusion in a Fluid Membrane with a Flexible Cortical Cytoskeleton
Diffusion in a Fluid Membrane with a Flexible Cortical Cytoskeleton
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DOI：
10.1016/j.bpj.2008.10.038
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发表时间：
2009-02-04
影响因子：
3.4
通讯作者：
Gov, Nir S.
中科院分区：
文献类型：
--
作者：
Auth, Thorsten;Gov, Nir S.
我们计算了固定在流体膜上的长链蛋白质柔性网络对该膜中蛋白质扩散的影响。这是皮质细胞骨架和红细胞脂质双层的模型，我们用它来预测细胞骨架对移动带 3 蛋白扩散系数的影响。利用细胞骨架施加在膜上的压力场，根据扩散蛋白和细胞骨架丝之间的空间排斥，我们定义了双层内扩散的潜在景观。我们研究了去除一种类型的锚蛋白后扩散系数的变化，例如在几种溶血性贫血中，以及细胞骨架的各向同性和各向异性拉伸。我们预测，由于空间频率以及势垒高度的降低，较少数量的锚定蛋白的扩散会总体增加，并且在拉伸方向上各向异性拉伸的扩散会增加。
We calculate the influence of a flexible network of long-chain proteins, which is anchored to a fluid membrane, on protein diffusion in this membrane. This is a model for the cortical cytoskeleton and the lipid bilayer of the red blood cell, which we apply to predict the influence of the cytoskeleton on the diffusion coefficient of a mobile band 3 protein. Using the pressure field that the cytoskeleton exerts on the membrane, from the steric repulsion between the diffusing protein and the cytoskeletal filaments, we define a potential landscape for the diffusion within the bilayer. We study the changes to the diffusion coefficient on removal of one type of anchor proteins, e.g., in several hemolytic anemias, as well as for isotropic and anisotropic stretching of the cytoskeleton. We predict an overall increase of the diffusion for a smaller number of anchor proteins and increased diffusion for anisotropic stretching in the direction of the stretch, because of the decrease in the spatial frequency as well as in the height of the potential barriers.