Figure 1. Photo-activated switch for controlling enzymatic reactions.
A. Illustration of a model enzymatic reaction.Substrates (S) can be converted to product (P) by enzymes (E), during which light emission (yellow) by non-stable intermediates directly reflects reaction rate. B. Enzymatic reaction organized by subcellular compartments. Under the same overall concentration of enzymes and substrates, a reaction will be accelerated if enzymes and substrates are co-localized in a limited space, resulting in increasing local substrates concentration, thus increasing effective collision between substrates and enzymes (right). On the other hand, if enzymes are isolated from substrates, the reaction rate will decrease (left).C. General design of rearranging enzymes distribution by light. Each member in a light-responsive protein pair is fused with either phase separating protein or an enzyme of interest (EOI) to form phase module or light-responsive module. The phase module can phase separate into a membraneless compartment. Upon light induction, these two modules will bind to each other, and thus EOI can entry the compartment. D. General principle of concentrating chemicals into the compartment. Substrates will be enriched in the compartment if the substrate-protein interactions are similar to protein-protein interactions promoting phase separation (e.g., pi-pi interaction).