The influence of membrane lateral pressures on simple geometric models of protein conformational equilibria
The influence of membrane lateral pressures on simple geometric models of protein conformational equilibria
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DOI：
10.1016/s0009-3084(99)00054-7
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发表时间：
1999-08-01
影响因子：
3.4
通讯作者：
Cantor, RS
中科院分区：
文献类型：
--
作者：
Cantor, RS
许多内在膜蛋白的功能需要构象转变，这通常受到蛋白质嵌入的双层的分子组成的强烈影响。最近，这种转变的构象平衡的机制被建议，其中有人认为，在分布的侧向压力的双层脂质组合物的变化所导致的转变改变了蛋白质构象转变的机械功的量，如果在蛋白质的横截面积分布的变化与深度内的双层。由于几乎没有任何蛋白质的跨膜区的形状变化的信息，各种简单的几何模型被认为是。对于一个通用的模型，和更具体的模型，近似可能的合作重排束中的Cl-螺旋，它被发现，构象平衡取决于侧压力分布的第一和第二积分矩。除了揭示可能的物理基础的众所周知的蛋白质活性和双层脂质的“非层状”倾向之间的相关性，这种依赖的时刻的压力曲线允许预测的相对影响不同的脂质成分的变化，即使在没有特定的蛋白质形状变化的信息。酰基链长度，顺式不饱和度和位置的变化，以及胆固醇和小的界面活性溶质（正烷醇）的影响进行了比较。(C)1999爱思唯尔科学爱尔兰有限公司保留所有权利。
The function of many intrinsic membrane proteins requires a conformational transition that is often strongly influenced by the molecular composition of the bilayer in which the protein is embedded. Recently, a mechanism for this shift in conformational equilibrium was suggested, in which it is argued that a shift in distribution of lateral pressures of the bilayer resulting from a change in lipid composition alters the amount of mechanical work of the protein conformational transition, if the change in the cross-sectional area profile of the protein varies with depth within the bilayer. As there is little information on the change in shape of the transmembrane region of any protein, various simple geometric models are considered. For both a generic model, and more specific models that approximate likely cooperative rearrangements of cl-helices in bundles, it is found that the conformational equilibrium depends on the first and second integral moments of the lateral pressure distribution. In addition to revealing the possible physical underpinnings of the well-known correlation between protein activity and the 'nonlamellar' tendency of bilayer lipids, this dependence on moments of the pressure profile allows for prediction of the relative effects of different lipid compositional changes even in the absence of information on specific protein shape changes. Effects of variation in acyl chain length, degree and position of cis-unsaturation, and addition of cholesterol and small interfacially-active solutes (n-alkanols) are compared. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.