Antigenicity of polypeptides (poly alpha amino acids). XV. Studies on the immunogenicity of synthetic polypeptides in mice.

The response of mice to synthetic linear polypeptides of known composition but random sequence has been studied. Neither Swiss mice nor a number of inbred strains could respond to copolymers of only 2 amino acids (G(60)L(40), G(60)A(40), G(90)T(10)). Upon introduction of as little as 4 mole per cent of a third amino acid, good immune responses were obtained, regardless of the nature of the third amino acid. The level of the immune response to a series of glu-lys-ala polymers increased with increasing alanine content of the polymer.