Feedback circuits in biochemical networks which underly cellular signaling
pathways are important elements in creating complex behavior. A specific aspect
thereof is how stability of equilibrium points depends on model parameters. For
biochemical networks, which are modelled using many parameters, it is typically
very difficult to estimate the influence of parameters on stability. Finding
parameters which result in a change in stability is a key step for a meaningful
bifurcation analysis. We describe a method based on well known approaches from
control theory, which can locate parameters leading to a change in stability.
The method considers a feedback circuit in the biochemical network and relates
stability properties to the control system obtained by loop--breaking. The
method is applied to a model of a MAPK cascade as an illustrative example