Abstract
In this study, we propose an application methodology of the Nyquist criterion for biochemical reaction systems with the biological negative feedback loops. The molecular robot or a real biochemical reaction system such as an intracellular signal transduction system utilizes negative feedback regulation to enhance the stability and robustness. However, since such a system tends to be a high dimensional, nonlinear, and complex system with multiple feedback loops, it is troublesome to quantitatively evaluate the stability property of the whole system in terms of a particular feedback loop. We show that by modifying the system gain the Nyquist criterion can be appreciable for this problem, and as a result the stability margin can be calculated.
