Immune responses of inbred guinea pigs to the sequential polymer poly(L-Tyr-L-Ala-Gly): studies with the oligomers of the polymers.

Synthetic known sequence polypeptides poly(Tyrosine-Glutamic acid-Alanine-Glycine) T-G-A-Gly), were found to be very immunogenic in responder inbred guinea pigs. Two and one-half micrograms were enough to elicit both humoral and cellular responses. Only the alpha-helical oligomers were immunogenic and were able to inhibit the homologous antigen-antibody reactions. The random polymers of comparable amino acid composition, i.e., poly(glutamic acid60alanine40) (GA), poly(glutamic acid50 tyrosin50) (GT), poly(glutamic acid60alanine30tyrosine10)(GAT10), did not inhibit. The antibodies against (T-G-A-Gly)n did not bind to the closely related known sequence polymer poly tyrosine-alanine-glutamic acid-glycine) (T-A-G-Gly)n or to the above random polymers. It is thus concluded that antibodies against (T-G-A-Gly)n are directed against conformational determinats.