Immunochemical characterization and serum concentrations of pregnancy-associated serum proteins in mice

The glycoprotein structure of two pregnancy-associated murine proteins, alpha 1-PAMP and alpha 2-PAMP, was analysed by using concanavalin A (Con A) affinity electrophoresis: alpha 1-PAMP was completely precipitated by free Con A, whereas alpha 2-PAMP showed heterogeneity. The isoelectric points of alpha 1-PAMP and alpha 2-PAMP were determined at 4.2 and 4.0 respectively by using crossed immunoelectrofocusing. The alpha 2-PAMP was detectable only in the serum of pregnant mice and fetuses. Maternal serum concentrations increased from Day 8 of pregnancy, remained at high values between Days 14 and 18, and could not be detected by 2 days post partum.