NEUTRAL SALTS: THE GENERALITY OF THEIR EFFECTS ON THE STABILITY OF MACROMOLECULAR CONFORMATIONS

The effects of various neutral salts on the temperature of the thermally-induced denaturation of the globular protein ribonuclease are described and compared with the effects of these salts on helix-coil transition temperatures in other macromolecules. These agents affect the stability of the native form of macromolecules as diverse as ribonuclease, collagen, DNA, and myosin in very similar ways; salts such as KSCN and CaCl(2) serve as very potent general structural destabilizers or denaturants, while salts such as (NH(4))(2)SO(4) and K(2)HPO(4) strongly stabilize the native conformation. The effectiveness of the neutral salts as ribonuclease destabilizers is compared with that of urea and the guanidinium salts.