A continuum membrane model can predict curvature sensing by helix insertion.
A continuum membrane model can predict curvature sensing by helix insertion.
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DOI：
10.1039/d1sm01333e
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发表时间：
2021-12-08
期刊：
影响因子：
3.4
通讯作者：
Johnson ME
中科院分区：
文献类型：
--
作者：
Fu Y;Zeno WF;Stachowiak JC;Johnson ME
蛋白质结构域，如ENTH（Epsin N-末端同源性）和BAR（bin/amphiphysin/rvs），含有驱动优先结合弯曲膜的两亲性螺旋。然而，预测这些域的物理参数如何控制这种“曲率感测”行为是具有挑战性的，由于在大球体的表面上的纳米级螺旋所产生的局部膜变形。我们在这里使用一个可变形的连续模型，该模型考虑了膜的物理特性和螺旋插入来预测曲率传感行为，并对多个实验数据集进行了直接验证。我们表明，插入可以建模为膜的自发曲率的局部变化，产生良好的协议与ENTH结合囊泡和圆柱体，和ArfGAP螺旋囊泡的实验中提取的能量。对于具有高曲率的小囊泡，插入通过减轻膜上的应变来降低膜能量，所述膜上的应变远离其优选的零曲率。然而，对于较大的囊泡，插入具有相反的效果，通过引入更多的应变来破坏膜的稳定性。我们在这里制定了一个经验表达式，准确地捕捉数值计算的膜能量作为两个基本的膜特性（弯曲模量κ和半径R）以及插入的螺旋（和面积Ains）施加的应力的函数。因此，我们预测这些物理参数将如何改变螺旋结合弯曲囊泡，这是一个重要的步骤，了解他们的本地化动态膜重塑过程中的能量。
Protein domains, such as ENTH (Epsin N-terminal homology) and BAR (bin/amphiphysin/rvs), contain amphipathic helices that drive preferential binding to curved membranes. However, predicting how the physical parameters of these domains control this ‘curvature sensing’ behavior is challenging due to the local membrane deformations generated by the nanoscopic helix on the surface of a large sphere. We here use a deformable continuum model that accounts for the physical properties of the membrane and the helix insertion to predict curvature sensing behavior, with direct validation against multiple experimental datasets. We show that the insertion can be modeled as a local change to the membrane’s spontaneous curvature, , producing excellent agreement with the energetics extracted from experiments on ENTH binding to vesicles and cylinders, and of ArfGAP helices to vesicles. For small vesicles with high curvature, the insertion lowers the membrane energy by relieving strain on a membrane that is far from its preferred curvature of zero. For larger vesicles, however, the insertion has the inverse effect, de-stabilizing the membrane by introducing more strain. We formulate here an empirical expression that accurately captures numerically calculated membrane energies as a function of both basic membrane properties (bending modulus κ and radius R) as well as stresses applied by the inserted helix ( and area Ains). We therefore predict how these physical parameters will alter the energetics of helix binding to curved vesicles, which is an essential step in understanding their localization dynamics during membrane remodeling processes.
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影响因子：
2.4
作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
Baumgart, Tobias
DOI：
10.1073/pnas.1605259113
发表时间：
2016-08-30
影响因子：
11.1
作者：
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通讯作者：
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