Sabra M C, Uitdehaag J C, Watts A
Department of Biochemistry, University of Oxford, England.
Biophys J. 1998 Sep;75(3):1180-8. doi: 10.1016/S0006-3495(98)74037-8.
Based on experimental evidence for 2D array formation of bacteriorhodopsin, we propose a general model for lipid-mediated 2D array formation of membrane proteins in lipid bilayers. The model includes two different lipid species, "annular" lipids and "neutral" lipids, and one protein species. The central assumption of the model is that the annular lipids interact more strongly with the protein than with the neutral lipids. Monte Carlo simulations performed on this model show that 2D arrays of proteins only form when there are annular lipids present. In addition, no arrays form if all of the lipids present are annular lipids. The geometry of the observed arrays is for the most part hexagonal. However, for a certain range of low annular lipid/protein ratios, arrays form that have geometries other than hexagonal. Using the assumption that the hydrocarbon chains of the annular lipids are restricted in motion when close to a protein, we expand the model to include a ground state and an excited state of the annular lipids. The main result from the extended model is that within a certain temperature range, increasing the temperature will lead to larger and more regular protein arrays.
基于细菌视紫红质二维阵列形成的实验证据，我们提出了一个脂质介导的膜蛋白在脂质双层中形成二维阵列的通用模型。该模型包括两种不同的脂质种类，即“环形”脂质和“中性”脂质，以及一种蛋白质种类。该模型的核心假设是环形脂质与蛋白质的相互作用比与中性脂质的相互作用更强。对该模型进行的蒙特卡罗模拟表明，只有当存在环形脂质时，蛋白质的二维阵列才会形成。此外，如果所有存在的脂质都是环形脂质，则不会形成阵列。观察到的阵列的几何形状大部分是六边形的。然而，对于一定范围的低环形脂质/蛋白质比率，会形成非六边形几何形状的阵列。利用环形脂质的烃链在靠近蛋白质时运动受限的假设，我们将模型扩展到包括环形脂质的基态和激发态。扩展模型的主要结果是，在一定温度范围内，升高温度将导致更大、更规则的蛋白质阵列。
