Kinetic analysis of reversible closed bicyclic enzyme cascades covering the whole course of the reaction.

A kinetic analysis of the closed bicyclic enzyme cascades is presented. 1. It includes the dependence on time from the onset of the reaction, of the concentration of the modified and unmodified enzyme species involved and the time course equations of the modificational fractions of the interconvertible enzymes. 2. The transient phase equations obtained allow the definition of new regulatory modification properties. 3. The expressions for concentrations of the unmodified and modified forms of the interconvertible enzymes, as well as those of the fractional modifications in the steady state are derived as particular cases of the general equations. 4. These steady state expressions coincide with those obtained by other authors. 5. The analytical results obtained are discussed in relation to the Escherichia coli glutamine synthetase cascade.