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.)

Physical form

Supplied as a solution in 20 mM Tris, pH 7.5, with 150 mM NaCl.

Application

Human carbonic anhydrase II has been used in a study to assess quantitative imaging of mitochondrial and cytosolic free zinc levels in an in vitro model of ischemia/reperfusion. Human carbonic anhydrase II has also been used in a study to investigate a new scrubber concept for catalytic CO₂ hydration.

Biochem/physiol Actions

Carbonic anhydrase is a zinc metalloenzyme that catalyzes the hydration of carbon dioxide to carbonic acid. It is involved in vital physiological and pathological processes such as pH and CO₂ homeostasis, transport of bicarbonate and CO₂, biosynthetic reactions, bone resorption, calcification, and tumorigenicity. It is required for renal acidification. Its absence can lead to osteoporosis, renal tubular acidosis, and cerebral calcification. Therefore, this enzyme is an important target for inhibitors with clinical applications in glaucoma, epilepsy and Parkinson’s disease. In addition, it is being explored as a potential target for obesity and cancer. 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 facilitation of CO₂ elimation. Sulfonamides, sulfamates and sulfamides are potent inhibitors of CA.