Influence of Scan Rate on Simulation of Differential Scanning Calorimetry Profiles of Protein Denaturationt
The heat capacity has played a major role in proteins. Its calculation by atomistic simulation methods remains a significant challenge due to the complex and dynamic nature of protein structures and this work compares the denaturation effect of bovine carbonic anhydrase (BCA) by heat, pH and scan rate dependence of protein denaturation by molecular dynamics (MD) simulation. To better understand this factor on calculating a protein heat capacity and Tm, we have provided a comparative analysis of simulation models that differ in their scan rate and pH description. Our model protein system is the carbonic anhydrase, and a series of 20 ns simulated DSC with different scan rate (v= 0.10, 0.0125, 0.015 and 0.02 K/ps) and pH have been reported by simulated annealing performed at temperatures ranging from 250 to 575 K, starting from the carbonic anhydrase native structure. It was observed that, our systems were quite sensitive to the description and the calculated melting temperature (Tm) varied in the range 353-438 K and was higher for higher scan rates systems and lower for acidic condition. It was also demonstrated that increasing scan rate causes a slight shift to right and acidic pH cause a shift to left in Tm value.
