Configurable Linear Control of Biochemical Systems

International audienceThe advancements of synthetic biology make biochemical systems of increasing complexity realizable in living cells. Many computation and control design examples have been demonstrated either in vivo or in vitro. In principle, any polynomial ordinary differential equation can be approximated by chemical reaction networks [1]. 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 [2], 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 this paper 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. Hence implementing linear control systems in biochemistry can be made more practical