EFFECTS OF MUTATIONS ON THE THERMODYNAMICS OF PROTEINS

Results obtained by means of differential scanning calorimetry (DSC) a nd isothermal titration calorimetry (ITC) with several proteins and mu tant forms thereof are reported. DSC has been employed primarily to de termine the thermodynamic changes accompanying the thermally induced u nfolding of proteins, and ITC to measure the thermodynamics of the int eractions of proteins with various ligands. It has become inreasingly evident that we are dealing with very complicated systems in which a s ingle amino acid replacement probably causes numerous small effects wh ich are widely distributed in the molecule, and which add up to an obs erved effect that is obviously difficult to rationalize in terms of mo lecular structure. It is nevertheless important to continue to broaden the base of quantitative information in the field.