Curvature coupling dependence of membrane protein diffusion coefficients.
Curvature coupling dependence of membrane protein diffusion coefficients.
复制标题
膜蛋白扩散系数的曲率耦合依赖性。
作者：
Stefan M Leitenberger;Ellen Reister;U. Seifert
我们考虑蛋白质的横向扩散与膜的曲率相互作用。如果粒子处于具有与粒子的自发曲率一致的特定曲率的膜位置，则相互作用能最小化。我们采用随机模拟，考虑到膜的热波动和颗粒的扩散行为。在本研究中，我们忽略了颗粒对膜动力学的影响，因此膜动力学与自由波动膜的动力学一致。总的来说，我们发现，这种曲率耦合大大提高了扩散系数。我们比较的比率的预测或测量的扩散系数和自由的膜内扩散系数，这是一个参数的模拟，依赖于几个近似的分析结果。我们发现，模拟总是导致一个稍微小的扩散系数比从我们的分析方法。作用在颗粒上的力的相关性的详细研究表明，扩散夹杂物试图遵循膜上的有利位置，使得力沿着轨迹平均小于随机颗粒位置。
We consider the lateral diffusion of a protein interacting with the curvature of the membrane. The interaction energy is minimized if the particle is at a membrane position with a certain curvature that agrees with the spontaneous curvature of the particle. We employ stochastic simulations that take into account both the thermal fluctuations of the membrane and the diffusive behavior of the particle. In this study, we neglect the influence of the particle on the membrane dynamics, thus the membrane dynamics agrees with that of a freely fluctuating membrane. Overall, we find that this curvature coupling substantially enhances the diffusion coefficient. We compare the ratio of the projected or measured diffusion coefficient and the free intramembrane diffusion coefficient, which is a parameter of the simulations, with analytical results that rely on several approximations. We find that the simulations always lead to a somewhat smaller diffusion coefficient than that from our analytical approach. A detailed study of the correlations of the forces acting on the particle indicates that the diffusing inclusion tries to follow favorable positions on the membrane such that forces along the trajectory are on average smaller than they would be for random particle positions.