Thermal inactivation and conformational lock of carbonic anhydrase

• Main Authors: علایی, ل, امانی, مجتبی, موسوی موحدی, علی اکبر
• Format: Text
• Language: Persian
• Published: 1389
• Subjects: QU بیوشیمی; Carbonic acid
• Online Access: https://eprints.arums.ac.ir/2087/; https://eprints.arums.ac.ir/2087/1/carbonic.pdf

Carbonic Anhydrase is an enzyme that assists inter-conversion of carbon dioxide and water into carbonic acid, protons and bicarbonate ions. Zinc is the key to this enzyme reaction. The water bound to the zinc ion is broken down to a proton and hydroxyl ion. Zinc is a positively charged ion; it stabilizes the negatively charged hydroxyl ion so that it is ready to attack the carbon dioxide. Since this enzyme produces and uses protons and bicarbonate ions, it plays a key role in the regulation of pH and fluid balance in different parts of body. Carbonic Anhydrase isozymes perform different functions at their specific locations, and their absence or malfunction can lead to diseased states, ranging from the loss of acid production in the stomach, kidney failure and glaucoma. Blocking this enzyme shifts the fluid balance in the eyes of the patient to reduce fluid buildup, thereby relieving pressure. Inhibitors of carbonic Anhydrase are being used to treat glaucoma via enzyme activity inhibition. In this report, the enzyme activity was measured based on p-nitrophenol formation. Optimum activities were achieved at pH 6.8. Thermal inactivation temperature and kinetic parameters such as Km, kcat,Vmax and kcat/Km(enzyme efficiency) was obtained by UV-Vis spectrophotometer .The size of the enzyme was compared by dynamic light scattering (DLS) for native and inactive states. In this work, we report the structural information such as the number of interactions between subunits, kinetic parameters, enzyme efficiency as well as the size of carbonic Anhydrase in two states of native and inactive forms.