EFFECTS OF MUTATIONS ON THE THERMODYNAMICS OF PROTEINS

Results obtained by means of differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC) with several proteins and mutant forms thereof are reported. DSC has been employed primarily to determine the thermodynamic changes accompanying the thermally induced unfolding of proteins, and ITC to measure the thermodynamics of the interactions of proteins with various ligands. It has become inreasingly evident that we are dealing with very complicated systems in which a single amino acid replacement probably causes numerous small effects which are widely distributed in the molecule, and which add up to an observed effect that is obviously difficult to rationalize in terms of molecular structure. It is nevertheless important to continue to broaden the base of quantitative information in the field.