Studies on artifical antigens. I. Antigenicity of DNP-polylysine and DNP copolymer of lysine and glutamic acid in guinea pigs.

Dinitrophenyl conjugates of poly-L-lysine, varying in percentage conjugation and molecular weight have been found to induce skin reactivity and precipitating antibodies in guinea pigs. At best, 40 per cent of immunized animals developed delayed and immediate responses to DNP-polylysine, which is believed to reflect constitutional differences among the animals assayed. Only those animals capable of responding to DNP-polylysine, responded to an immunologically distinct poly-alpha-amino acid consisting of glutamyl and lysyl residues ("copolymer glu-lys"). The percentage of animals responding to the DNP-polylysine antigen decreased as the degree of DNP conjugation increased.