Rat renal and erythrocyte carbonic anhydrases. Purification and properties.

Rat renal and erythrocyte carbonic anhydrases (carbonate hydro-lyase, EC 4.2.1.1) were isolated by affinity chromatography. The erythrocytes contain two major forms of the enzyme. One of the forms has a specific activity (towards CO2) 30 times higher than the other and constitutes the major part of the total cellular carbonic anhydrase. The amino acid compositions of this high-activity type and of the low-activity type are similar to the compositions reported for these types in other species. The kidney appears to have only one high-activity form of carbonic anhydrase which is very similar to and probably identical with the erythrocyte high-activity form.