21 Carbonic Anhydrase

Carbonic anhydrase—aromatic sulfonamide complexes, a resonance Raman study

“…1) is seen in the reduction of the intensity of this band upon binding. Consistent with the X-ray evidence for the shape of the cleft [4], perturbation from planarity is small since the -N=N-frequency does not shift significantly upon binding.…”

“…1). The presence of the -S02N-H form is strong evidence that the sulfonamido group remains in the co-ordination sphere of the Zn in going from the crystalline [4] to the aqueous complex.…”

“…This class of inhibitors is of great importance in studies of the physiological function of carbonic anhydrase [4]. X-ray crystallography [4] and spectroscopic studies [ S,6] have shown that the inhibitor is bound in a hydrophobic cleft in the enzyme with the sulfonamido group probably within the co.ordination sphere of the zinc ion. However, the detailed geometry of the co-ordination is not yet known.…”

Affinity chromatography of carbonic anhydrase

“…The enzyme carbonic anhydrase is strongly and specifically inhibited by aromatic and heterocyclic sulfonamides [8,9]. These inhibitors would be expected to be useful in designing biospecific adsorbents for the enzyme.…”

“…After adsorption of the enzyme to the column elution can be brought about in a predictable manner by agents that are known to act competitively with sulfonamides. The human erythrocyte enzyme, as described elsewhere [9] , consists of a mixture of two forms that differ from each other in the structure of the binding site for inhibitors. This difference can be utilized to separate the two isoenzymes by selective displacement after adsorption on a chromatography column.…”