Artificial Molecular Motors

Molecular motors are protein assemblies that use chemical energy to perform mechanical tasks in living cells. Synthetic motors have been created using small molecules (Nobel prize 2016) or DNA building blocks. Proteins, on the other hand, Nature’s choice of material, have to date almost not been used.

Compared to DNA, proteins offer a much larger variety of possible designs and greater opportunity to learn principles important for biological motors.

Here we will continue a long-term effort to construct artificial protein motors, with the long-term aim to help understand the operational and engineering principles of bio-molecular motors.Specifically, we recently succeeded in expressing and assembling Tumbleweed (TW), one of the most ambitious, functional protein designs ever attempted.

It is a three-legged protein construct designed to step along a DNA track, powered by externally controlled changes in ligand concentration. Here we aim to provide direct, visual evidence of controlled stepping, and to begin optimizing its performance. We have also synthesized Lawnmower (LM) a burnt-bridges motor that can run autonomously, powered by protease activity.

We will systematically improve its performance, and learn how to harness its motion for applications by controlling its motion along complex nanofabricated tracks.

Finally, we will begin work on the “holy grail” of protein engineering: the design and synthesis of a synthetic, fully autonomous, enzymatic protein motor.