Fast crystallization of rotating membrane proteins
Fast crystallization of rotating membrane proteins
复制标题
旋转膜蛋白的快速结晶
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
M. Shelley
中科院分区：
文献类型：
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作者：
Naomi Oppenheimer;David B. Stein;M. Shelley
我们研究在膜上运动的主动旋转蛋白之间的相互作用。实验证据表明，这种旋翼蛋白，就像线粒体内膜的ATP合酶一样，可以将自己排列成晶格。我们表明结晶是可能通过转子蛋白之间的流体动力学和排斥相互作用的组合。特别是，流体动力相互作用诱导转子蛋白质组装的旋转运动，在排斥力的存在下，驱动系统进入六边形晶格。整个晶体旋转的角速度随电机密度的增加而增加，随晶格直径的减小而减小——更大和更稀疏的阵列旋转速度较慢。旋转相互作用允许蛋白质的组合样品配置和达到一个有序的稳定状态，这是无法达到淬灭的非旋转系统。因此，旋转相互作用作为一种消除无序的温度，但实际的热扩散会导致膨胀和无序。相反，旋转相互作用在空间上是有界的。因此，一旦达到有序状态，就会一直保持它。
We examine the interactions between actively rotating proteins moving in a membrane. Experimental evidence suggests that such rotor proteins, like the ATP synthases of the inner mitochondrial membrane, can arrange themselves into lattices. We show that crystallization is possible through a combination of hydrodynamic and repulsive interactions between the rotor proteins. In particular, hydrodynamic interactions induce rotational motion of the rotor protein assembly that, in the presence of repulsion, drives the system into a hexagonal lattice. The entire crystal rotates with an angular velocity which increases with motor density and decreases with lattice diameter — larger and sparser arrays rotate at a slower pace. The rotational interactions allow ensembles of proteins to sample configurations and reach an ordered steady state, which are inaccessible to the quenched nonrotational system. Rotational interactions thus act as a sort of temperature that removes disorder, except that actual thermal diffusion leads to expansion and loss of order. In contrast, the rotational interactions are bounded in space. Hence, once an ordered state is reached, it is maintained at all times.