K. Koyama et al., STUDIES ON THE EPITOPE OF PIG ZONA-PELLUCIDA RECOGNIZED BY A FERTILIZATION-BLOCKING MONOCLONAL-ANTIBODY, Journal of Reproduction and Fertility, 1996, pp. 135-142
Heat solubilized pig zona pellucida (pZP) was separated into four majo
r glycoprotein families (pZP1, pZP2, pZP3, pZP4). Cloning of a full-le
ngth cDNA coding for pZP1 revealed that the coding sequence for pZP4 w
as immediately followed by the sequence for the amino-terminal residue
of pZP2 and that they shared a significant similarity with mouse and
human ZP2, which are considered to serve as a secondary sperm receptor
in sperm-zona interactions. One of the monoclonal antibodies, mAb-5H4
, produced against pZP4 inhibited the binding of boar and human sperma
tozoa to each of the homologous oocytes. The epitope recognized by mAb
-5H4 was determined to be present on a 10 amino acid sequence of pZP1(
50-59) by using epitope mapping and analysis of chain flexibility of p
ZP4. A synthetic 18mer peptide corresponding to pZP1(50-67) reacted wi
th mAb-5H4, and mouse antisera raised to the synthetic 18mer peptide r
ecognized intact pig zona pellucida and strongly inhibited the fertili
zation of pig oocytes with boar spermatozoa in vitro. These results su
ggest that the pZP4 peptide (50-59) identified as an epitope for mAb-5
H4 could be a promising candidate in the development of a contraceptiv
e vaccine.