Thermodynamic study on conformation change of carbonic anhydrase

The effect of pHs on structural stability of the zinc-containing metalloenzyme carbonic anhydrase has been studied by means of differential scanning calorimetry. The rule of the conformational change for the enzyme with pH change has been found by thermodynamic analysis. The experimental results also provide valuable information: in the pH range from 5.26 to 9.04, two independent endothermal peaks were observed on DSC thermogram. It shows the existence of two structural domains in the molecule. The transition temperature and enthalpy of the two domains are different.