Wheat germ agglutinin (WGA) binds to the entire surface of Strongylocentrotus purpuratus sperm, and inhibits the egg jelly-induced acrosome reaction. The binding was found to be species dependent and was completely inhibited by 5 mM N-acetyl-D-glucosamine. Blockage of the acrosome reaction by WGA was bypassed by a combination of the ionophores A23187 and monensin, although neither ionophore was effective individually. These experiments suggest that WGA blocks both Ca2+ uptake and Na+/H+ exchange in these sperm, which was confirmed by direct measurements of 45Ca2+ uptake and H+ efflux. The target of WGA in S. purpuratus sperm appears to be a membrane glycoprotein of Mr = 210,000. Treatment of this protein with neuraminidase or endo-beta-N-acetylglucosaminidase F abolished WGA binding.
Wheat germ agglutinin blocks the acrosome reaction in Strongylocentrotus purpuratus sperm by binding a 210,000-mol-wt membrane protein.
S B Podell, V D Vacquier; Wheat germ agglutinin blocks the acrosome reaction in Strongylocentrotus purpuratus sperm by binding a 210,000-mol-wt membrane protein.. J Cell Biol 1 November 1984; 99 (5): 1598–1604. doi: https://doi.org/10.1083/jcb.99.5.1598
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