A different structural feature for carbonic anhydrases in human erythrocytes

This study presents a different structural feature for carbonic anhydrase in human erythrocytes Carbonic anhydrase isozymes (CA-I and CA-II) were purified from an erythrocyte pool of 20 healthy subjects. For purification, Sepharose-4B-L-tyrosine-sulfanilamide affinity column was used. Resnets from 3-10 % discontinuous SDS-polyacrylamide gel electrophoresis (SDS-PAGE) showed a single band for CA-I and two distinct bands for CA-II. The molecular weights of the two bands were similar. One peak for CA-I and two peaks for CA-II were obtained in gel filtration. The enzymatic activities of the bands in question were also of different value. Native electrophoresis showed two bands for CA-I, and it showed three bands for CA-Tr. It can be concluded that CA-I is a polymer composed of a single promoter and CA-II has three different polymers composed of two distinct promoters, suggesting a new structural feature of human erythrocyte carbonic anhydrase isozymes.