Nanopore Machines

Life at the nanoscale is full of surprises. As our understanding of the molecular world evolves, a great challenge is to synthesize and assemble systems that are capable of performing work or completing sophisticated tasks at the molecular scale. Commonly referred to as molecular machines or nanomachnes, these dynamic systems are designed to respond to a variety of external stimuli.

Biological nanopores are ideal building materials in nanotechnology because they have a robust and well-defined structure that self-assemble on biological membranes in a controllable manner. The aim of this research is to design and assemble artificial machine that are able to perform work, selectively transport a cargo or undergo directional motion.

• A Nanopore Piston

We use chemical and protein engineering techniques to introducing emergent functions into biological nanopores.

In a notable example, depicted below, we interlocked a DNA rod into a protein cylinder to form a membrane bound molecular machine that transports selected DNA molecules through the nanopore against an applied potential.

• Protein Rotaxane

We created other interlocked system in which protein rotaxane in which a polypeptide thread is encircled by a Cytolysin A (ClyA) nanopore and capped by two protein stoppers. The rotaxane could be switched between two states. At low potential (<-50 mV) the rotaxane is assembled, and at high potentials (-100 mV) the rotaxane is disassembled. This system might find applications in nanoscale memory systems or single-molecule sensors.