Carbonic anhydrase. Purification and nature of the enzyme

2 described a new enzyme present in red blood corpuscles which catalyses both phases of the reversible reaction: H2CO3, CO2 + H20. They purified this enzyme from mam- malian erythrocytes and gave a detailed account of its properties and the kinetics of the reactions which it catalyses. The greatly purified enzyme preparation obtained by them had a very high catalytic activity, was a colourless substance free from haematin and from other known enzymes, stable within pH 3-12, thermolabile, and very sensitive to KCN, H2S, NaN3 and to several heavy metals.