Differences in the Amino Acid Composition of a Third Rabbit Antibody

Antibody directed against a neutral hapten, p-amino-β -phenyl lactoside, has been purified, and its amino acid composition has been determined. When the results were compared with the previous analyses of two rabbit antibodies, small but significant differences were found. The demonstration of a third unique antibody composition supports the hypothesis that the amino acid differences are related to specificity rather than to the heterogeneity of γ -globulin.