Carbonic Anhydrase (CA; carbonate hydro-lyase, EC 4.2.1.1)), a zinc containing enzyme, catalyzes reversible hydration of carbon dioxide.
This metalloenzyme is found in animals, photosynthesizing organisms, and in some nonphotosynthetic bacteria. Thermal denaturation of the protein was studied by enzymatic activity, circular dichroism, and differential scanning calorimetry. The results showed that CA thermal
denaturation is an irreversible process. Fitting DSC data and consideration of the validity of two-state model realized to conclude CA undergoes irreversible thermal denaturation in one step. Using this model activation energy, T* parameter (the absolute temperature at
which the rate constant of denaturation is equal to 1 min−1), and total enthalpy of CA denaturation were calculated
