Department of Applied Science, University of California, Davis, California 95616, USA.
Nat Mater. 2012 Dec;11(12):1074-80. doi: 10.1038/nmat3451. Epub 2012 Oct 21.
Liquid-crystalline phases of stacked lipid bilayers represent a pervasive motif in biomolecular assemblies. Here we report that, in addition to the usual smectic order, multicomponent multilayer membranes can exhibit columnar order arising from the coupling of two-dimensional intralayer phase separation and interlayer smectic ordering. This coupling propagates across hundreds of membrane lamellae, producing long-range alignment of phase-separated domains. Quantitative analysis of real-time dynamical experiments reveals that there is an interplay between intralayer domain growth and interlayer coupling, suggesting the existence of cooperative multilayer epitaxy. We postulate that such long-range epitaxy is solvent-assisted, and that it originates from the surface tension associated with differences in the network of hydrogen-bonded water molecules at the hydrated interfaces between the domains and the surrounding phase. Our findings might inspire the development of self-assembly-based strategies for the long-range alignment of functional lipid domains.
堆叠脂质双层的液晶相代表生物分子组装中普遍存在的主题。在这里，我们报告说，除了通常的近晶有序外，多组分多层膜可以表现出柱状有序，这是由二维层内相分离和层间近晶有序的耦合引起的。这种耦合可以在数百个膜薄片中传播，从而产生相分离域的长程取向。对实时动力学实验的定量分析表明，层内域生长和层间耦合之间存在相互作用，这表明存在协同多层外延。我们假设这种长程外延是溶剂辅助的，它起源于与水合界面处氢键水分子网络的差异相关的表面张力，这些界面存在于域和周围相之间。我们的发现可能会激发基于自组装的策略的发展，以实现功能脂质域的长程取向。
