Wong J Y, Majewski J, Seitz M, Park C K, Israelachvili J N, Smith G S
Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA.
Biophys J. 1999 Sep;77(3):1445-57. doi: 10.1016/S0006-3495(99)76992-4.
This neutron reflectometry study evaluates the structures resulting from different methods of preparing polymer-cushioned lipid bilayers. Four different techniques to deposit a dimyristoylphosphatidylcholine (DMPC) bilayer onto a polyethylenimine (PEI)-coated quartz substrate were examined: 1) vesicle adsorption onto a previously dried polymer layer; 2) vesicle adsorption onto a bare substrate, followed by polymer adsorption; and 3, 4) Langmuir-Blodgett vertical deposition of a lipid monolayer spread over a polymer-containing subphase to form a polymer-supported lipid monolayer, followed by formation of the outer lipid monolayer by either 3) horizontal deposition of the lipid monolayer or 4) vesicle adsorption. We show that the initial conditions of the polymer layer are a critical factor for the successful formation of our desired structure, i.e., a continuous bilayer atop a hydrated PEI layer. Our desired structure was found for all methods investigated except the horizontal deposition. The interaction forces between these polymer-supported bilayers are investigated in a separate paper (Wong, J. Y., C. K. Park, M. Seitz, and J. Israelachvili. 1999. Biophys. J. 77:1458-1468), which indicate that the presence of the polymer cushion significantly alters the interaction potential. These polymer-supported bilayers could serve as model systems for the study of transmembrane proteins under conditions more closely mimicking real cellular membrane environments.
这项中子反射率研究评估了由不同方法制备聚合物缓冲脂质双层所产生的结构。研究了四种将二肉豆蔻酰磷脂酰胆碱（DMPC）双层沉积到聚乙烯亚胺（PEI）涂层石英基底上的不同技术：1）囊泡吸附到先前干燥的聚合物层上；2）囊泡吸附到裸基底上，随后进行聚合物吸附；以及3、4）将铺展在含聚合物亚相上的脂质单分子层进行Langmuir-Blodgett垂直沉积以形成聚合物支撑的脂质单分子层，然后通过3）脂质单分子层的水平沉积或4）囊泡吸附形成外部脂质单分子层。我们表明，聚合物层的初始条件是成功形成我们所需结构（即在水合PEI层顶部形成连续双层）的关键因素。除了水平沉积外，在所研究的所有方法中都发现了我们所需的结构。这些聚合物支撑的双层之间的相互作用力在另一篇论文中进行了研究（Wong, J. Y., C. K. Park, M. Seitz, and J. Israelachvili. 1999. Biophys. J. 77:1458 - 1468），该论文表明聚合物缓冲层的存在显著改变了相互作用势。这些聚合物支撑的双层可以作为在更接近模拟真实细胞膜环境的条件下研究跨膜蛋白的模型系统。
