The Effect of Neutral Salts on the Hydrogen Ion Dissociation Curves of Proteins

That the titration curves of proteins are modified in shape and position by the presence of neutral salts is well known. The general nature of the effects which are to be anticipated on the basis of interionic attraction theory have been considered by a number of authors and have been shown to be qualitatively consistent with the limited experimental data available. A more extensive body of observations is, however, necessary for a comprehensive examination of this problem over a wide range of pH and of salt concentration. The purpose of my paper is to present a brief summary of observations which have accumulated over a period of years in my laboratory and to offer a preliminary analysis of some of them. Our studies have been confined to two proteins—crystalline egg albumin and the crystalline globulin which Palmer isolated from the albumin fraction of cow's milk. Attention will be directed chiefly...