CARBONIC-ANHYDRASE ACTIVATORS .13. ARYL-ETHYLAMINES AND HETARYL-ETHYLAMINES ARE POTENT NONCOMPETITIVE ACTIVATORS OF ESTERASIC ACTIVITY OF ISOZYME-II

Typical carbonic anhydrase (CA) activators for the CO2 hydration react ion (such as histamine, adrenaline, noradrenaline or isoprotenerol) we re found to activate the enzyme for 4-nitrophenylacetate hydrolysis re action too. A kinetic study was done using bovine CA II, both for CO2 hydration reaction in the presence of these activators (using a stoppe d-flow technique), as well as for the hydrolysis of 4-nitro-phenylacet ate (by a spectrophotometric method). The kinetic data indicate a non- competitive type of interaction between enzyme, substrates and activat ors.