Carbonic anhydrase and urease: an investigation in vitro on the possibility of a synergic action

The indirect interactions between the carbonic anhydrase (CA) and urease (UR) are investigated in the present work using rate determinations detected by combined potentiometric measurements. It is shown that, in accord with the mass-action law for the two enzyme catalyzed reactions, the two enzymes assume a synergic pattern: the increase in the rate of removal of CO2 from the solution facilitated by CA increases the rate of production of NH3 consequent from urea dissociation. The experimental system which has been set up to monitor these interactions consists of a potentiometric apparatus to follow the gaseous exchanges of CO2 and NH3 which take place from a buffered solution containing both CA and UR. The results of the present work are consistent with, and add a further support to the finding of Dodgson and Forster, who first demonstrated in vivo the existence of an indirect linkage between urea production and CA catalytic activity.