Isolation and biological characterization of boar sperm capacitation-related antigen

PROBLEM: Monoclonal anti-capacitated sperm antibody has been used as a prob e to identify, isolate, and characterize specific, fertilization-related an tigen with some characteristic features that point to its possible signific ance in immunocontraception. METHOD OF STUDY: Fast protein liquid chromatography (FPLC), enzyme-linked i mmunosorbent assay (ELISA), sodium dodecyl sulfate polyacrylamide gel elect rophoresis (SDS-PAGE), and isoelectrofocusing were used for isolation, immu nochemical and physicochemical characterization of a monoclonal antibody (m Ab) 1F10 cognate antigen. Sperm-zone pellucida binding and hemizona assay w ere used for resting the biological roles of mAb 1F10 and Ag 1F10 in boar a nd human fertilization processes. RESULTS: The AE 1F10 was found to be eluted in the eighth protein peak of F PLC-fractionated Nonidet P40 (NP40) extracts of capacitated boar spermatozo a. The SDS-PAGE and immunoelectrofocusing experiments showed that Ag 1F10 i s a protein composed of a single peptide chain with a relative molecular ma ss of 68/70 kDa and an isoelectric point of 3.5. It was demonstrated that t he zona binding activity of spermatozoa preincubated in the presence of mAb 1F10 was significantly inhibited both in porcine and human in vitro fertil ization (IVF) systems. A dose-dependent manner of inhibition of the sperm/l igand activities of porcine and human zone pellucida was observed when the effect of purified Ag 1F10 was investigated by its preincubation with zona pellucida. CONCLUSIONS: It is assumed that the protein bearing the epitope recognized by mAb 1F10 may be accepted as one of the molecules with receptor function in sperm-zone pellucida interaction during fertilization.