Table 1.
Sequences of the hCG-derived peptides displayed on the VLP.
Fig 1.
Agarose gel electrophoresis of the wild type and the recombinant VLPs.
The particles contain RNA and are therefore visualized by staining with ethidium bromide. The differences in mobility are consequences of alterations in VLP surface charge due to the presence the foreign peptides. Each peptide is identified with numbers corresponding to the amino acid residues at its N- and C-terminal boundaries in the hCGß sequence. 5AS refers to the cPiPP antibody affinity selectant (see text for details).
Fig 2.
ELISA of anti-sera from mice immunized with VLPs displaying the various peptides described in the text.
As controls panel A shows that anti-PP7 serum reacts with the PP7 VLP but not with hCG. Also shown is reaction of an anti-hCG monoclonal antibody with hCG. Panel B shows reaction with hCG of antisera generated by immunization of mice with each of the indicated peptide-displaying VLPs. In each case, three mice were immunized, and the values plotted here are the averages.
Fig 3.
Neutralization of hCG bioactivity by anti-hCG serum.
The upper and lower panels show the results of two independent experiments in which immature mice were injected for three consecutive days with 100μl of PBS containing 200ng of hCG plus sera from mice immunized with the various VLPs identified by the peptides they display (see the text). Also shown are control experiments without serum (no serum), with neither serum nor hormone (no serum no hormone) and with anti-MS2 serum (MS2, present only in the lower panel). The results are presented as mg of uterine weight per 100 grams body weight.