"Membrane transport systems: ion channels, complexity, and functional dissipative assembly"

生物——人、植物、细菌——有两个关键特征：我们不断地消耗能量，并燃烧这些能量来维持细胞的组织结构。这种维持结构的能量流动组合，被描述为耗散自组装，允许我们的细胞在复杂的反应网络中执行无数的功能。受大自然的启发，超分子化学家已经能够模仿细胞生命的某些方面。化学家在创造自组装结构方面取得了相当大的成功，有时是在（相对）复杂的反应网络中，但这些结构只在能量最小值附近组装，因此被称为平衡自组装。我们也已经成功地模仿了一些与生命相关的非生物成分的功能：复制、催化、膜运输、传感。已经创造了耗散自组装宏观结构的例子，当能量流被移除时，这些结构将不复存在；然而，已知的例子没有任何我们认为是类似生命的功能。

Living creatures - people, plants, bacteria - have two key characteristics: we continually consume energy, and we burn that energy to maintain the organized structures of our cells. This combination of energy flow to maintain structure, described as dissipative self-assembly, allows our cells to perform a myriad of functions in complex reaction networks. Inspired by nature, supramolecular chemists have been able to mimic some aspects of cellular life. Chemists have had considerable success in creating self-assembled structures, sometimes from within (relatively) complex reaction networks, but these are only assembled near the energy minimum hence are described as equilibrium self-assembly. We have also had success in mimicking some types of functions associated with life using non-living components: replication, catalysis, membrane transport, sensing. Examples of dissipative self-assembled macroscopic structures have been created which cease to exist when the energy flow is removed; however the known examples do not have any functions we might recognize as life-like. The overall objective of this proposal is to create dissipative self-assembled structures that have a membrane transport function. Building on our strengths, the specific targets include ion channels that will require a continual supply of chemical fuel or a continuously applied membrane potential, in order to continue to act. These transport systems will be reaction networks that control a molecular-level function in the same ways that cells do. The path from current examples to systems to fulfill the objectives is not long; we have most of the tools in hand for the first steps, but foresee a need and opportunity to develop new experimental membrane systems suitable for investigation of these systems in cell-like architectures. The novelty of this proposal is that dissipative self-assembled systems will move beyond structure to function. The proposal goals are inherently conceptual with potential impact across supramolecular chemistry, but the links from transport models to practical spin-offs are very tight.