Guided assembly of functional macromolecular building blocks: Carbon NanoMembranes (CNM) and Purple Membranes (PM)

将生物分子大分子组装到各种表面是当今最先进的技术。然而，“独立式”超分子组装体的受控排列仍处于起步阶段，主要是因为这种结构单元具有太高的分子质量，以至于不能利用布朗运动使它们接触，从而使它们能够彼此反应并组装它们。我们的目标是通过组装碳纳米膜（CNM）和紫膜（PM）来实现这一愿景。CNM是芳族两亲分子的单分子交联层，其横向尺寸为几平方厘米，厚度约为1 nm。盐生盐杆菌的PM是细菌视紫红质（BR）和脂质的膜组装体，BR是一种光驱动的质子泵。数万BR的排列在一个六方晶格的形式在脂质双层的PM。本项目的目标是建立混合结构，包括作为功能基板的CNM和取向共价组装PM。这种混合结构是普遍感兴趣的（i）关于其制备技术和（ii）鉴于其光电性质和作为介观构建块，例如在光驱动的海水淡化中。 在平方厘米范围内，存在多种方法用于其表面的化学改性，CNM的导电性和其预期的质子导电性。选择PM作为生物细胞器样超分子组装体是因为嵌入的BR分子的预取向及其容易的遗传修饰，PM具有吸引人的功能特性，即光电电压产生和光驱动质子运输，和物理-所获得的功能组件不应需要任何额外的机械支撑，使得其可用作建筑物更复杂的系统中。

The assembly of biomolecular macromolecules to surfaces of various kinds is state-of-the-art today. However, controlled arrangement of 'free-standing' supramolecular assemblies is still in its infancy, mainly because the building blocks of that kind have a too high molecular mass to utilize Brownian motion only to bring them into contact, so that they can react with each other, and assemble them. We aim to move towards this vision by assembling carbon nanomembranes (CNM) and purple membranes (PM). CNM are monomolecular cross-linked layers of aromatic amphiphilic molecules with lateral dimensions of several square centimeters and a thickness of about 1 nm. PM from Halobacterium salinarum is a membrane-assembly of bacteriorhodopsin (BR), which is a light-driven proton pump, and lipids. Several ten thousand BRs are arranged in form of a hexagonal crystalline lattice in the lipid bilayer of the PM.The goal of this project is to build hybrid structures comprising CNM as a functional substrate and oriented covalently assembled PMs. Such a hybrid structure is of general interest (i) concerning the techniques of its preparation and (ii) in view of its photoelectric properties and as a mesoscopic building block for example in light-driven sea-water desalination.The choice of CNMs as substrates for these supramolecular assemblies is motivated by their tensile strength, the possibility to produce them with large areas, i.e. in the square centimeter range, the existence of a manifold of ways for the chemical modification of their surface, the electric conductivity of the CNMs and their expected proton conductivity. The choice of PM as the biological organelle-like supramolecular assembly is because of the preorientation of the embedded BR molecules and their easy genetic modification, the PMs attractive functional properties, i.e. photoelectric voltage generation and light-driven proton transport, and the physico-chemical robustness of the PM.The functional assembly obtained should not require any additional mechanical support so that it can be used as a building block in more complex systems later on.