The Pellucida Glycoprotein ZP 3-Binding Protein of the Boar Spermatozoa

Four protein components have been isolated from the CHAPS extract of boar spermatozoa by chromatography on PSL-Sepharose affinity column and cellulose CM-52 ion exchange column sequentially. Both boar sperm protein SP1and SP2 exhibited binding activity with the zona pellucida glycoprotein ZP3 by immobilized zona pellucida glycoprotein binding assay (IZPGBA), and SP2 also showed hemagglutinating activity. The protein SP1 obviously inhibited sperm-oocyte binding when it was preincubated with oocytes. The inhibitory activity of SP1 was related to its concentration. By using Western blot technique and biotinylated ZP3, a Zp3-binding spermatozoa protein with molecular weight of 68 kD was identified, which may be a protein involved in sperm-oocyte binding.