Synthesis and degradation of interconvertible enzymes. Kinetic equations of a model system

Steady-state and kinetic equations have been developed which characterize the rates of formation, interconversion, and degradation of an enzyme protein subject to reversible phosphorylation. The theoretical model system incorporates separate fractional degradative rate constants for the phosphorylated and dephosphorylated protein species. The classical models for interconvertible enzymes, and for protein turnover, are special limiting situations of the general model presented here.