Immunological comparison of glycopeptides obtained from haptoglobin types 1-1, 2-1 and 2-2.

Immunochemical properties of glycopeptides III and IV obtained from haptoglobin (Hp) types 1-1, 2-1, and 2-2, by trypsin digestion were studied by double immunodiffusion test, quantitative precipitation and crossed immunoelectrophoresis with antisera directed against Hp 1-1, Hp 2-1, and Hp 2-2, respectively. Trypsin digestion resulted in an exposition in the glycopeptide IV 1-1 of the antigenic determinant characteristic of Hp 1-1, which had been hidden inside the molecule of the native Hp 1-1. On the contrary, it was not possible to find an antigenic determinant characteristic of the product of alpha 2 gene.