中文摘要：

<正>Dear Sir,Carbonic anhydrase(CA) is a kind of zinc enzyme that reversibly catalyzes hydration of CO2.Sixteen CA isoenzymes have been described in mammals[1].These isozymes play physiological roles in erythrocytes,including CO2transport,ion secretion,pH regulation and so forth.CA1and 2 are both cytosolic enzymes that are found in large quantities in erythrocytes.Excluding hemoglobin,CA1 is the

英文摘要：

Carbonic anhydrase （CA） is a kind of zinc enzyme that reversibly catalyzes hydration of CO2. Sixteen CAisoenzymes have been described in mammals . These isozymes play physiological roles in erythrocytes, including CO2 transport, ion secretion, pH regulation and so forth. CA1 and 2 are both cytosolic enzymes that are found in large quantities in erythrocytes. Excluding hemoglobin, CA I is the most abundant protein in erythrocytes