Photoswitchable single-stranded DNA-peptide coacervate formation as a dynamic system for reaction control.

In cells, segregation allows for diverse biochemical reactions to take place simultaneously. Such intricate regulation of cellular processes is achieved through the dynamic formation and disassembly of membraneless organelles via liquid-liquid phase separation (LLPS). Herein, we demonstrate the light-controlled formation and disassembly of liquid droplets formed from a complex of polylysine (pLys) and arylazopyrazole (AAP)-conjugated single-stranded DNA. Photoswitchablility of droplet formation was also shown to be applicable to the control of chemical reactions; imine formation and a DNAzyme-catalyzed oxidation reaction were accelerated in the presence of droplets. These outcomes were reversed upon droplet disassembly. Our results demonstrate that the photoswitchable droplet formation system is a versatile model for the regulation of reactions through dynamic LLPS.