The Antigenic Properties of a Protein Compounded with Casein

One of the most promising methods of attack on the obscure problem of 'biological specificity would seem to lie in the search for newly formed antigenic properties in proteins compounded either of non-antigenic proteins, or of an antigenic with a non-antigenic protein. It was with this method in mind .that we sought for possible antigenic properties in the mixture of the amino acids (glutamic acid plus leucin) in the proportion in Which they occur in casein ( i ) . No success was obtained in this case, however. We have since studied in more detail the antigenic properties of protamin (salmin) as compared with a compound substance that it forms with casein. The preparation of the pure casein that we have employed and the properties of a potent antiserum to i,t have been discussed in the previous article. The methods of preparing protamin and protamin caseinate are as follows: