Kinetics of a model for zymogen activation: the case of high activating enzyme concentrations.

Transient phase and steady state equations have been derived for the following enzyme activation mechanism: (formula; see text) in which the concentrations of activating enzyme, E, and substrate, A, are greatly in excess of that of zymogen, Ei. EEi, EEa, EaA and EaY are four intermediates; W is a peptide related from Ei during EEa formation and X and Y are the products of Ea reaction on A. From the general equations, approximate solutions under certain simplifying conditions have been derived. Finally, some formal particular cases of the above mechanism are considered.