TERMINATION OF PREGNANCY IN MICE FOLLOWING ADMINISTRATION OF ANTIBODIES TO THE PENTADECAPEPTIDE-10-24 OF CHICKEN RIBOFLAVIN CARRIER PROTEIN- IDENTIFICATION OF A BIONEUTRALIZING EPITOPE OF CHICKEN RIBOFLAVIN CARRIER PROTEIN

Our studies have shown that the administration of antibodies to chicke n riboflavin carrier protein (cRCP) or disulfide-reduced carboxymethyl ated cRCP (RCM-RCP) leads to termination of pregnancy in mice. In an a ttempt to delineate the bioneutralizing epitopes, a combination of che mical modification and predictive methods was used. The results led to the identification of the region 10-24 of cRCP as a potential candida te. A single injection of antipeptide antibodies to pregnant mice on d ay 11 resulted in 100% pregnancy termination. This was accompanied by a drastic reduction in circulatory progesterone as early as 24 h after the antibody administration. These results thus demonstrate that the amino acid sequence 10-24 of cRCP harbours a bioneutralizing epitope o f cRCP.