Kinetic behaviour of proenzymes activation in the presence of different inhibitors for both activating and activated enzymes.

In the present paper, a kinetic analysis of a general model for proenzyme activation, where the activating enzyme and also the activated one are reversibly inhibited in two steps by two different inhibitors, has been performed. The cases in which both inhibitors are the same, or in which the inhibition is irreversible (only one or the two inhibition routes) are treated as particular cases of the general model. In addition, the kinetic behaviour of many other proenzyme activation systems involving inhibition, particular cases of the reaction scheme under study, can be obtained. The total number of particular cases for the general model under study is 370, so this approach offers to the scientific community working in limited proteolysis regulation for the first time a method based on general solutions which only needs to be specified to their concrete problem of zymogen activation. Finally, new adimensional parameters are introduced, allowing the knowledgement, in the case that any of the inhibition routes is irreversible, the relative weight of both activation and irreversible inhibition routes.