Temperature sweep test to determine the thermal stability of BSA
In order to determine the thermal stability of BSA, temperature sweep test was conducted for the three temperature ranges, 25-50-25°C, 25-65-25°C and 25-75-25°C at the rate of 1°C/ min. The sample was analyzed at three stages: “ONE”, “TWO” and “THREE”. The thermal hysteresis data are shown in Figure 1. In the temperature sweep range 25-50°C, the absorbance value clearly indicates that the protein has not lost its original conformation. However, for the other two temperature ranges, significant differences between the absorbance values at “ONE” and “THREE” were observed. This indicated the loss of reversibility of the BSA folding. The absolute error values between stages “ONE” and “THREE” were found to be 0.05±0.001, 0.09±0.002 and 0.15±0.01 for 25-50°C, 25-65°C and 25-75°C ranges, respectively. Similarly, absorbance changes (%) with respect to initial value of BSA solution were estimated to be 1.6%, 2.9% and 4.8% for the above three conditions, respectively. This highlighted the irreversible unfolding of BSA of 65°C and 75°C, which are above its melting temperature.