Kinetic traps in chemically fueled self-assembly and how to overcome them.

Nature uses dynamic, molecular self-assembly to create cellular architectures that adapt to their environment. For example, a guanosine triphosphate (GTP)-driven reaction cycle activates and deactivates tubulin for assembly into microtubules and disassembly. Inspired by dynamic self-assembly in biology, multiple studies have developed synthetic analogs of assemblies regulated by chemical chemically fueled reaction cycles. A challenge in most of these studies is that molecules assemble upon activation but do not disassemble upon deactivation. In other words, they remain kinetically trapped, and the resulting assemblies are not dynamic. In this work, we show how molecular design dictates the tendency of deactivated molecules to remain trapped in the assembled state. We also show how molecular design can be used to tune the dynamics of the reaction cycle. Our work should result in chemically fueled assemblies that are truly dynamic in that dis-assembly immediately follows deactivation.