Time delays in metabolic control systems.

The authors employed mathematical models with discrete and distributed time delays. They assumed unknown kinetics for pathway intermediates. The models were used to simulate stability transitions. Discrete delay models were first analyzed for oscillatory potential. The study then incorporated cooperative inhibition effects. Distributed delay models were tested with non-monotonic kernels. Stability thresholds (Tc) were calculated for each case. The models allowed for comparisons between delay types and their effects.

Above a definite substrate concentration, a critical delay Tc was identified. Discrete delays may cause instability even without cooperative enzyme interactions. Cooperative inhibition was found to expand the instability domain. Distributed delays with non-monotonic kernels increased Tc values. The models showed that oscillations can emerge from delay effects alone. The study found that instability is not limited to cooperative enzyme systems. Delay types significantly influence the onset of oscillations. These findings suggest that time delays are key to pathway stability.

The authors suggest that time delays may be sufficient to cause instability in metabolic pathways. They propose that cooperative inhibition broadens the instability range. The models indicate that distributed delays can increase Tc values. The study supports the idea that delays are a potential source of oscillations. The researchers comment on the possibility that oscillations serve as physiological signals. They suggest that these signals may trigger adaptive strategies in cells. The findings imply that delays should be considered in pathway modeling. The authors emphasize the need for further analysis of delay effects.