Modeling the role of cyclic AMP in catabolite repression of inducible enzyme biosynthesis in mircobial cells

Abstract

Modeling the role of cyclic AMP (cAMP) in catabolite repression of inducible enzyme production in microbial cells was studied. A catabolite repression index, F, was defined based on the postulation that complex formation occurs between RNA polymerase (RNAP) and DNA, and shifting from the inert form to the open form of this complex (the latter form is required for transcription) is accelerated by the cAMP·CRP complex. The catabolite repression index, F, was incorporated into model equations of mRNA production. Empirical relationship between intracellular cAMP level and medium glucose concentration were established based on experimental data and introduced into the model. Computer simulation results were obtained for a number of interesting cases. The practical utility of the proposed model was demonstrated by comparing it with the experimental results on glucose isomerase biosynthesis.