Identification of carbohydrate-binding proteins in mammalian spermatozoa (human, bull, boar, ram, stallion and hamster) using [125I]fucoidin and [125I]neoglycoprotein probes.

A protein-carbohydrate recognition system is thought to be involved in the early stages of fertilization in mammals. In this investigation carbohydrate-binding proteins have been identified in extracts of human, bull, boar, ram, stallion and hamster spermatozoa using [125I]fucoidin and [125I]neoglycoproteins (BSA-fucose and BSA-mannose) to probe Western blots. Results show that proacrosin is the major protein species recognized in extracts of human, bull, boar and ram spermatozoa. In hamster and stallion spermatozoa, carbohydrate-binding activity was associated with several low molecular weight proteins that may or may not be related to active forms of acrosin. These results support the hypothesis that proacrosin is involved in secondary or consolidated binding of mammalian spermatozoa to the zona pellucida by virtue of its carbohydrate-binding capacity.