Expression of Cytosolic and Noncytosolic Carbonic Anhydrase Enzymes from Bovine Brain Membrane

Abstract

Carbonic anhydrase is an enzyme that takes responsibility in inhalation function but, until today, carbonic anhydrase is not examined if it is present in the bovine brain membrane or not. The enzyme carbonic anhydrase was purified and separately characterized according to the bonding forms in 4 steps such as outer peripheral, cytosolic, inner peripheral and integral. Affinity chromatography was used for purification of the enzyme in all four steps. The affinity column was prepared with sepharose-4B-L-tyrosine-sulphanilamide. Purified carbonic anhydrase was obtained at each step. Enzyme activity was measured by CO₂ hydratase activity and esterase activity methods. Optimum pH and optimum temperature were defined for purified enzymes at each step. Morover molecular weight and purity were detected by gel filtration and SDS-PAGE electrophorose. In addition, the enzyme's Km and n_max values were found with the Lineweaver- Burk method. The obtained results are discussed in comparison with other mammalian carbonic anhydrases. Carbonic anhydrase was shown to be exist in bovine brain membrane and this enzyme was optimized.