The Antigenicity of Some Synthetic Poly-Iminoacids I. ANTIGENIC PROPERTIES OF POLY-L-PROLINE.

The antigenic properties of a group of synthetic poly-iminoacids have been tested in guinea-pigs and rabbits by active cutaneous anaphylaxis, delayed skin hypersensitivity reactions, passive cutaneous anaphylaxis (PCA), tanned cell agglutination and agglutination-inhibition. The antigenicity of a linear homopolymer, poly-L-proline, has been demonstrated in guinea-pigs. This polymer exists in two forms differing only in their secondary structure, Form I having a righthanded helix and Form II a left-handed helix. That both forms are antigenic and yet non-cross-reacting emphasizes the importance of secondary structure in this system. Comparison of polyprolines of different molecular weights suggests the presence of more than one antigenic determinant; a polymer of an average molecular weight of 1500 was antigenically deficient compared with a polyproline of a molecular weight of 17,000. No cross-reactions were detected between anti-polyproline or anti-polyprolineglycine and collagen or its derivatives. The possible structure of the antigenic determinants involved is discussed. [ABSTRACT FROM AUTHOR]