Molecular Machines with Integrated Parts

ended

The widespread use of molecular-level motion in key natural processes suggests that great rewards could come from bridging the gap between the present generation of synthetic molecular machines—which by and large rely upon switching of individual components to carry out their functions—and the machines of the macroscopic world, which utilize the synchronized behaviour of integrated components to perform tasks more complex than the sum of the components. The aim of this project is to learn how to integrate the movements and chemistries of different molecular machine components. The proposed program is divided into three themes: Theme 1: Transport and synthesis by nanomechanical substrate positioning. We will integrate switching mechanisms with components that can attach and release a substrate, in order to develop methodology for the nanomechanical manipulation of substrates. We see this theme as reminiscent of the way that substrates are passed between sites in various enzyme complexes in biology. Theme 2: Sequence-selective synthesis using molecular assembly lines. We will integrate reactive molecular appendages with rotaxanes in which the macrocycle moves along a track through brownian motion, in order to develop molecular assembly lines. This theme is reminiscent of molecular-machine-mediated sequence specific polymerisation in biology, such as protein synthesis by the ribosome and DNA synthesis by some DNA polymerases. Theme 3: Transport with chemically fuelled molecular linear motors. We shall integrate ratchet mechanisms with chemically fuelled molecular pumps and walkers and use them to transport cargo between phases and to carry out synthesis via energy ratchet mechanisms induced by chemical fuels. This theme is reminiscent of how biological molecular motors drive chemical systems away from equilibrium, thereby enabling tasks to be performed, cargo to be transported directionally and work to be done.