Dissipative assembly of a membrane transport system†
A membrane system consisting of a transport-inactive thiol-terminated oligoester and a channel-forming amine-terminated thioester is subject to kinetic control though the provision of a chemical fuel. Intermolecular thioester exchange occurs rapidly between the fuel and the inactive thiol to produce the channel-forming species. Spontaneous intramolecular degradation of the active compound with release of a lactam occurs more slowly to reform the inactive thiol. The system can cycle from transport inactive to active and back via injection of the fuel. Such behavior is consistent with dissipative assembly of the ion-channel function of the system.