CARBONIC-ANHYDRASE ACTIVATORS .8. PK(A)-ACTIVATION RELATIONSHIP IN A SERIES OF AMINO-ACID DERIVATIVES, ACTIVATORS OF ISOZYME-II

Activation of isoenzyme II of carbonic anhydrase (CA II) was investigated for a series of amino acids and some of their derivatives, with pK(a)-s in the range 6.0-12.5. Excepting for the compounds possessing aromatic heterocyclic side chains, the plot of activation vs. pK(a) fits on a sigmoid curve. This was compared with the corresponding plot of azoles and bisazoles investigated earlier, with pK(a)-s in the range 2,5-8.0. Over the whole pH range, the activation curves seem to be bell-shaped. The mechanism of action of the activators is also discussed.