Reversibly Bound Kinesin-1 Motor Proteins Propelling Microtubules Demonstrate Dynamic Recruitment of Active Building Blocks.

Biological materials and systems often dynamically self-assemble and disassemble, forming temporary structures as needed and allowing for dynamic responses to stimuli and changing environmental conditions. However, this dynamic interplay of localized component recruitment and release has been difficult to achieve in artificial molecular-scale systems, which are usually designed to have long-lasting, stable bonds. Here, we report the experimental realization of a molecular-scale system that dynamically assembles and disassembles its building blocks while retaining functionality. In our system, filaments (microtubules) recruit biomolecular motors (kinesins) to a surface engineered to allow for the reversible binding of the kinesin-1 motors. These recruited motors work to propel the cytoskeletal filaments along the surface. After the microtubules leave the motors behind, the trail of motors disassembles, releasing the motors back into solution. Engineering such dynamic systems may allow us to create materials that mimic the way in which biological systems achieve self-healing and adaptation.