Sperm-zona pellucida (ZP) interaction, involving the binding of sperm surface ligands to complementary carbohydrates of ZP, is the first direct gamete contact event crucial for subsequent gamete fusion and successful fertilization in mammals. It is a complex process mediated by the coordinated engagement of multiple ZP receptors forming high-molecular-weight (HMW) protein complexes at the acrosomal region of the sperm surface. The present article aims to review the current understanding of sperm-ZP binding in the four most studied mammalian models, i.e., murine, porcine, bovine, and human, and summarizes the candidate ZP receptors with established ZP affinity, including their origins and the mechanisms of ZP binding. Further, it compares and contrasts the ZP structure and carbohydrate composition in the aforementioned model organisms. The comprehensive understanding of sperm-ZP interaction mechanisms is critical for the diagnosis of infertility and thus becomes an integral part of assisted reproductive therapies/technologies.

• Keywords
• ZP-ligands, gamete interaction, sperm-ZP receptors, spermatozoa, zona pellucida,
• MeSH
• Humans MeSH
• Ligands MeSH
• Membrane Glycoproteins metabolism   MeSH
• Cell Communication * MeSH
• Receptors, Cell Surface metabolism   MeSH
• Mammals metabolism   MeSH
• Spermatozoa cytology   metabolism   MeSH
• Zona Pellucida metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Names of Substances
• Ligands MeSH
• Membrane Glycoproteins MeSH
• Receptors, Cell Surface MeSH

The complete covalent structure of a novel boar DQH sperm surface protein resistant to many classical procedures of enzymatic fragmentation was determined. The relative molecular mass of the major form of this protein determined by ESI-MS and MALDI-MS was 13,065.2+/-1.0 and 13,065.1, respectively. However, additional peaks differing by 162 Da (i.e., minus hexose), 365 Da (i.e., minus hexose and N-acetylhexosamine), 146 Da (i.e., plus deoxyhexose), and 291 Da (i.e., plus sialic acid) indicated the heterogeneity due to differences in glycosylation. The complete covalent structure of the protein was determined using automated Edman degradation, MALDI-MS, and post-source decay (PSD) MALDI-MS, and shown to consist of N-terminal O-glycosylated peptide followed by two fibronectin type II repeats. The carbohydrates are O-glycosidically linked to threonine 10, as confirmed by PSD MALDI-MS of the isolated N-terminal glycopeptide. Eight cysteine residues of the protein form four disulfide bridges, the positions of which were assigned from MALDI-MS and Edman degradation data. We conclude that mass spectral techniques provide an indispensable tool for the detailed analysis of the covalent structure of proteins, especially those that are refractory to standard approaches of protein chemistry.

• MeSH
• Glycoproteins chemistry   MeSH
• Glycosylation MeSH
• Protein Conformation MeSH
• Membrane Glycoproteins chemistry   MeSH
• Molecular Sequence Data MeSH
• Molecular Weight MeSH
• Swine MeSH
• Amino Acid Sequence MeSH
• Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization MeSH
• Carrier Proteins chemistry   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• DQH sperm surface protein, Sus scrofa MeSH Browser
• Glycoproteins MeSH
• Membrane Glycoproteins MeSH
• pAIF-1 protein, Sus scrofa MeSH Browser
• Carrier Proteins MeSH