Wallace Elizabeth J, Hooper Nigel M, Olmsted Peter D
School of Biochemistry & Microbiology, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom.
Biophys J. 2006 Jun 1;90(11):4104-18. doi: 10.1529/biophysj.105.062778. Epub 2006 Mar 13.
We investigate the competing effects of hydrophobic mismatch and chain stretching on the morphology and evolution of domains in lipid membranes via Monte Carlo techniques. We model the membrane as a binary mixture of particles that differ in their preferred lengths, with the shorter particles mimicking unsaturated nonraft lipids and the longer particles mimicking saturated raft lipids. We find that phase separation can be induced upon increasing either the ratio J/kappa of the hydrophobic surface tension J to the compressibility modulus kappa. J/kappa determines the decay length for thickness changes. When this decay length is larger than the system size the membrane remains mixed. Furthermore, increasing the thickness relaxation time can induce transient phase separation.
我们通过蒙特卡罗技术研究了疏水失配和链拉伸对脂质膜中结构域形态和演化的竞争效应。我们将膜模拟为具有不同优选长度的粒子的二元混合物，较短的粒子模拟不饱和非筏脂质，较长的粒子模拟饱和筏脂质。我们发现，增加疏水表面张力J与压缩模量κ的比值J/κ，均可诱导相分离。J/κ决定了厚度变化的衰减长度。当该衰减长度大于系统大小时，膜保持混合状态。此外，增加厚度弛豫时间可诱导瞬态相分离。
