Response-Retaliation Behavior in Synthetic Protocell Communities.

Two different artificial predation strategies are spatially and temporally coupled to generate a simple tit-for-tat mechanism in a ternary protocell network capable of antagonistic enzyme-mediated interactions. The consortium initially consists of protease-sensitive glucose-oxidase-containing proteinosomes (1), non-interacting pH-sensitive polypeptide/mononucleotide coacervate droplets containing proteinase K (2), and proteinosome-adhered pH-resistant polymer/polysaccharide coacervate droplets (3). On receiving a glucose signal, secretion of protons from 1 triggers the disassembly of 2 and the released protease is transferred to 3 to initiate a delayed contact-dependent killing of the proteinosomes and cessation of glucose oxidase activity. Our results provide a step towards complex mesoscale dynamics based on programmable response-retaliation behavior in artificial protocell consortia.