65503-43-7 Antigen, poly 18 Poly 18 Poly 18 antigen Poly eyk(eya)5 l-Alanine, L-alpha-glutamyl-L-tyrosyl-L-lysyl-L-alpha-glutamyl-L-tyrosyl-L-alanyl-L-alpha-glutamyl-L-tyrosyl-L-alanyl-L-alpha-glutamyl-L-tyrosyl-L-alanyl-L-alpha-glutamyl-L-tyrosyl-L-alanyl-L-alpha-glutamyl-L-tyrosyl-, homopolymer