Nonadditive Compositional Curvature Energetics of Lipid Bilayers.
Nonadditive Compositional Curvature Energetics of Lipid Bilayers.
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DOI：
10.1103/physrevlett.117.138104
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发表时间：
2016-09-23
影响因子：
8.6
通讯作者：
Pastor RW
中科院分区：
文献类型：
--
作者：
Sodt AJ;Venable RM;Lyman E;Pastor RW
组成生物膜的单个脂质的独特性质共同决定了表面的能量学。表面的能量反过来又控制着膜结构的形成和膜重塑过程，因此将成为病毒融合、囊泡依赖性运输和与信号传导相关的横向组织的细胞尺度模型的基础。据我们所知，自然曲率总是被假定为可加的。这封信描述了观察到的意想不到的非添加剂组成的曲率能量的两个脂质必不可少的质膜：鞘磷脂和胆固醇的模拟。一个模型的开发，连接分子间的相互作用，曲率应力，并解释了当地组成的作用。胆固醇被证明可以降低饱和酰基链的有效库恩段的数量，降低弯曲的中性表面以下的侧压力，并有利于正曲率。对于不饱和（柔性）酰基链，未观察到该效应。同样地，鞘磷脂脂质之间的氢键导致正曲率，但仅在足够的浓度下，低于该浓度脂质优选负曲率。
The unique properties of the individual lipids that compose biological membranes together determine the energetics of the surface. The energetics of the surface in turn govern the formation of membrane structures and membrane reshaping processes, and will thus underlie cellular-scale models of viral fusion, vesicle-dependent transport, and lateral organization relevant to signaling. The spontaneous curvature, to the best of our knowledge, is always assumed to be additive. The letter describes observations from simulations of unexpected non-additive compositional curvature energetics of two lipids essential to the plasma membrane: sphingomyelin and cholesterol. A model is developed that connects molecular interactions to curvature stress, and which explains the role of local composition. Cholesterol is shown to lower the number of effective Kuhn segments of saturated acyl chains, reducing lateral pressure below the neutral surface of bending and favoring positive curvature. The effect is not observed for unsaturated (flexible) acyl chains. Likewise, hydrogen bonding between sphingomyelin lipids leads to positive curvature, but only at sufficient concentration, below which the lipid prefers negative curvature.