Section: New Results

Reconfigurable Circuitry in Biochemical Systems

Participants : Hui-Ju Chiang, François Fages, Sylvain Soliman.

Realizing complex systems within a biochemical environment is a common pursuit in synthetic biology. Such systems achieve certain computation through properly designed biochemical reactions. Despite fruitful progress being made, most existing reaction designs have fixed target functionality. Their lack of reconfigurability can be disadvantageous, especially when a system has to adapt to a varying biochemical environment.

When control systems are of concern, linear control is one of the most widely applied control methods. Any linear control system can be realized with three elementary building blocks: integration, gain, and summation. Realizing linear control with biochemical reactions has been proposed in previous work, where reaction rates of the underlying reactions play a key role to achieve the desired building blocks. Essentially the reaction rates have to be matched exactly, and it imposes serious practicality restriction because in reality the reaction rates of available reactions are predetermined and can be limited. In [16] we devise a mechanism to make linear control systems configurable by adding auxiliary species as control knobs. The concentrations of the auxiliary species can be adjusted not only to compensate reaction rate mismatch, but also to reconfigure different control systems out of the same control architecture.

Furthermore, in [15] we propose an analog approach to economically construct a reconfigurable logic circuit similar to a silicon based field programmable gate array (FPGA). The effective “logic” and “interconnect” of the circuit can be dynamically reconfigured by controlling the concentrations of certain knob species. We study a potential biomedical application of our reconfigurable circuitry to disease diagnosis and therapy at a molecular level.