[Antigenic structure of NCA-2 from meconium and comparison with normal fecal antigen from adult feces and carcinoembryonic antigen from malignant tissues].

Carcinoembryonic antigen (CEA)-related antigen were isolated from meconium and compared with those in adult feces and tumor tissues. NCA-2 and NCA preparations were isolated from meconium. By conventional anti-CEA antisera, NCA-2 from meconium, NFA-2 from adult feces and CEA from tumor tissues were indistinguishable from each other. However, the CEA-distinctive determinant was absent in NCA-2-molecules. The NFA-2-distinctive determinant was detectable in 20% of NCA-2-molecules. The molecular weight of purified NCA-2 was estimated to be 150,000 to 170,000 determined by SDS-PAGE. NCA-2 revealed beta-region mobility electrophoretically. NCA-2 had amino acid and carbohydrate compositions similar to those of CEA and NFA-2.