On the mechanism of action of carbonic anhydrase

The catalytic mechanism of the enzyme carbonic anhydrase has recently been the subject of renewed debate. The generally accepted picture of the mechanism of the enzyme's action has been thrown into doubt by new evidence derived from spectroscopic techniques. In this paper some of the points of conflict are examined and the degree is assessed to which new evidence is incompatible with the previously held picture of CA action. Reinterpretations are put forward of the mechanisms of proton transfer between enzyme and solution and of the detailed mechanism of ligand displacement at the zinc ion. These show that the generally accepted picture of the mechanism of CA action is by no means disproved and remains plausible.