Inhibition Effect of Eosin Y on Carbonic Anhydrase (CA) I and II Isoenzymes Purified from Human Erythrocytes

Abstract

All cells produce carbon dioxide (CO2), which is released as a result of metabolism and must be removed from the body. A large part of this CO2 is converted to bicarbonate by the carbonic anhydrase (CA) enzyme in erythrocytes and is discarded from the body. So, CA has a vital role in red blood cells. In addition to, CA involved in many other pathological and physiological processes and it was determined that the inhibitors of CA were effective in the treatment and diagnosis of many diseases particularly glaucoma. Considering the importance of the CA's inhibitors, in this study it was intended to research the inhibition effects of Eosin Y on CA I and CA II isoenzymes activity purified from human erythrocytes. Eosin Y is a dye molecule commonly used in histological and medical applications. For this purpose, firstly CA I and CA II isoenzymes were purified from human erythrocytes by using Sepharose-4B-L-tyrosine-sulfanilamide affinity chromatography. Then the inhibitory effect of Eosin Y on the activity of these human erythrocyte CA I (hCA I) and CA II (hCA II) isoenzymes was investigated. It was determined that hCA I and hCA II were inhibited by Eosin Y in the millimolar range. IC50 values were found to be 3.78 mM for hCA I and 2.04 mM for hCA II and Ki values were determined as 9.65±0.968 mM and 7.52±2.88 mM for hCA I and hCA II, respectively. In conclusion, it is hoped that the results obtained in this study may be beneficial in the development of new CA inhibitors which may be drug candidates.