Unit Definition

One Wilbur-Anderson (W-A) unit will cause the pH of a 0.02 M Trizma buffer to drop from 8.3 to 6.3 per min at 0 °C. (One W-A unit is essentially equivalent to one Roughton-Booth unit.)

Application

Human carbonic anhydrase isozyme II has been used to assess its gene fusion abilities for efficient expression and recovery of recombinant proteins. Human carbonic anhydrase isozyme II has also been used to investigate a new process for the synthesis of difluoromethanesulfonamides. Furthermore, CA II from Sigma has been used as a standard to measure the CA activity in lung tissue homogenates. The study analysed the possible relationship between the expression of carbonic anhydrase and non-small cell lung cancer. The product has also been used with Freund′s complete adjuvant at 1:1 ratio for antibody production. This study evaluated the quantitative and functional alterations of cytosolic CA isoenzymes in the erythrocytes of glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals. The enzyme has also been used in the study of natural phenolic inhibitors of CA II.

Biochem/physiol Actions

Carbonic anhydrase is a zinc metalloenzyme that catalyzes the hydration of carbon dioxide to carbonic acid. It is involved in pathological and physiological processes such as pH and CO₂ homeostasis, transport of bicarbonate and CO₂, biosynthetic reactions, bone resorption, calcification, and tumorigenicity. Therefore, this enzyme is an important target for inhibitors that can be used for treating various pathological conditions such as glaucoma, epilepsy and Parkinson’s disease. CAII has a molecular mass of approximately 30 kDa and is primarily present in type II pneumocytes. Due to this unique location it has been speculated that CAII is involved in pulmonary functions such as regulation of fluid secretion and CO₂ elimation. Sulfonamides, sulfamates and sulfamides are potent inhibitors of CA.