Evidence that peptides derived from the disintegrin domain of primate fertilin and containing the ECD motif block the binding of human spermatozoa to the zona-free hamster oocyte

The binding of human spermatozoa to, and penetration of zona-free hamster oocytes were significantly inhibited in the presence of (i) a 28-residue peptide corresponding to part of the disintegrin-like domain of monkey fertilin beta, or (ii) a hexapeptide containing the ECD motif found in the disintegrin-like domain of monkey and human fertilin beta, or (iii) a hexapeptide containing an RGD motif, implicated in integrin recognition. Polyclonal antibodies raised against the 28-residue peptide were used in conjunction with immunobeads to demonstrate that this peptide bound to the oolemma of zona-free hamster oocytes. These data support the view that the ECD motif is involved in the recognition of the oolemma receptor by human fertilin.