GERMYL AMINES AND GERMANOLS INHIBIT CARBONIC ANHYDRASE ISOZYME II BUT NOT ISOZYME I

The interaction of carbonic anhydrase (CA) isozymes I and II with Ge(IV) derivatives was investigated kinetically and spectrophotometrically, utilizing the native and Co(II)-substituted enzymes. Trimesitylgermyl amine and trimesitylgermanol act as uncompetitive inhibitors for isozyme CA II (with C0 2 and 4-nitrophenyl acetate as substrates) but they do not inhibit at all isozyme CA I. The related derivatives possessing carbon instead of germanium, i.e., triphenylcarbinol and triphenylmethylamine do not inhibit any of the two investigated CA isozyme. A mechanism explaining this behaviour is proposed.