Speaker
Description
Recent work has revealed that biochemical networks with bifunctional enzymes can display remarkably rich dynamics, including ultrasensitivity, switch-like responses, concentration robustness, and even species exhaustion. This talk presents a dynamical systems analysis of such networks, shedding light on the subtle architectural differences that produce these vast differences in functional behavior. We outline and employ the next-generation matrix method—only recently adapted to biochemical reaction networks—to characterize previously incomputable thresholds for the stability of boundary steady states. These thresholds are critical for determining when a mechanism will proceed or shut down. Using bifurcation analysis, we further establish conditions for multistationarity, showing how multiple positive steady states can arise within a single stoichiometric compatibility class—a property theorized to underlie toggle-switch behavior in genetic networks. Finally, we consider the capacity of such networks for absolute concentration robustness (ACR)—an essential feature of metabolic regulation—and explore the interplay between robustness and boundary stability.
