Heat Denaturation of Proteins by DSC

Introduction

Higher-order protein structures play a role in the function of a protein. Protein geometry, and therefore function, is greatly influenced by many factors, including the surrounding solvent, temperature, pH, etc. Therefore, the evaluation of protein stability in the presence of solvents and with respect to the pH of the environment is very important. One common method for analyzing protein stability is differential scanning calorimetry (DSC). DSC is used to measure heat energy released or absorbed by a sample compared to a reference, and is used to quantify the energy associated with chemical reactions, phase changes, and structural changes. When the higher-order structure of a protein is irreversibly changed, causing activity loss due to degeneration, this is referred to as thermal denaturation. The result is an endothermic peak in DSC analysis. Using the DSC-60 Plus differential scanning calorimeter, we measured the thermal denaturation temperatures of lysozyme and egg-derived protein, and observed the influence of pH on the thermal denaturation temperature of lysozyme.

May 13, 2015 GMT