COMPLEX DYNAMICS OF MASS-CLOSED COUPLED AUTOCATALYTIC SYSTEMS IN RESPONSE TO MINUTE ASYMMETRIC PERTURBATIONS

The role of kinetic coupling in catering to a remote-control mechanism for the onset and regulation of self-organization phenomena in a mult icompartmental biochemical system has been examined. Using two cyclic autocatalytic reaction networks operating in two chambers separated by a membrane and coupled through a common cofactor, it has been demonst rated that (i) in response to asymmetric perturbations, the coupled re action networks exhibit a variety of temporal self-organization phenom ena such as bistability, multiple periodicity, hard excitation and coe xistence of aperiodic oscillation with limit cycle even in mass-closed conditions; (ii) without disturbing a network directly, its dynamic b ehaviour can be regulated by perturbing some other network kinetically coupled to it and (iii) the dynamics of two coupled networks can be m ade to flip-flop between oscillatory and steady-states simply by modul ating the time of application of external perturbations. The extreme s ensitivity of this model to minute asymmetric fluctuations in the envi ronment can predict how the impact of local changes in physico-chemica l conditions can be transmitted from one compartment to another throug h coupled biochemical pathways in a living cell. (C) 1997 Elsevier Sci ence B.V.