ON THE SEROLOGICAL SPECIFICITY OF PEPTIDES.

With the idea that studies on the serological properties of peptides may ultimately aid in the understanding of the precipitin reactions of proteins, antigens have been prepared containing aminobenzoylated dipeptides, namely glycyl-glycine, glycyl-d, l-leucine, d, l-leucyl-glycine and d, l-leucyl-d, l-leucine. These four antigens were found to be different serologically, their specificity depending on the structure of the terminal amino acid carrying the free carboxyl group, and to a less degree also on the second amino acid. The results were obtained by means of precipitin and inhibition tests. Analogies to observations on enzyme specificity are discussed.