Dean D S, Manghi M
Laboratoire de Physique Théorique, UMR CNRS 5152, IRSAMC, Université Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 04, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Aug;74(2 Pt 1):021916. doi: 10.1103/PhysRevE.74.021916. Epub 2006 Aug 18.
We study a model lipid bilayer composed of a mixture of two incompatible lipid types which have a natural tendency to segregate in the absence of membrane fluctuations. The membrane is mechanically characterized by a local bending rigidity kappa(phi) which varies with the average local lipid composition phi. We show, in the case where kappa varies weakly with phi, that the effective interaction between lipids of the same type either can be everywhere attractive or can have a repulsive component at intermediate distances greater than the typical lipid size. When this interaction has a repulsive component, it can prevent macrophase separation and lead to separation in mesophases with a finite domain size. This effect could be relevant to certain experimental and numerical observations of mesoscopic domains in such systems.
我们研究了一种由两种不相容脂质类型混合组成的模型脂质双层，在没有膜波动的情况下，这两种脂质具有自然的分离倾向。该膜的力学特性由局部弯曲刚度κ(φ)表征，其随平均局部脂质组成φ而变化。我们表明，在κ随φ变化较弱的情况下，同类型脂质之间的有效相互作用要么在各处都具有吸引力，要么在大于典型脂质尺寸的中间距离处具有排斥成分。当这种相互作用具有排斥成分时，它可以防止宏观相分离，并导致在具有有限域尺寸的中间相中分离。这种效应可能与此类系统中介观域的某些实验和数值观测结果相关。
