猪精子凝集素在精卵结合中的作用机制

猪精子凝集素（ＢＳＬ）位于精子头部,既与精子蛋白结合,亦与透明带糖蛋白ＺＰ３结合。并且ＢＳＬ自身分子间亦会聚合。与ＺＰ３结合的片段亦结合于岩藻素－Ｓｅｐｈａｒｏｓｅ亲和柱,但不与胎球蛋白－Ｓｅｐｈａｒｏｓｅ柱结合。该片段具有较强的抑制精卵结合的活性。ＢＳＬ经ＮＢＳ修饰后,血凝活力大大下降,同时推动与精子结合的活性,但不影响它与ＺＰ３的结合。修饰后的ＢＳＬ亦显著抑制精卵结合。表明ＢＳＬ以两个不同的部

Mechanism of the Effect of Boar Sperm Lec tin on Sperm-oocyte Binding

Boar sperm lectin(BSL)located on the sperm head has been found to bind to both the sperm proteins and the zona pellucida glycoprotein ZP3.BSL also showed the intermolecular polymerization among themselves.The ZP3-binding BSL fragment was retained on fucoidan-Sepharose affinity column, but nto on fetuinSepharose column. This fragment exhibited a strong inhibitory effect on spermoocyte binding. When BSL was modified by NBS,its hemagglutinating activitydecreased to a large extent, and its binding activity with sperm was lost.The modified BSL also markedly inhibited sperm-oocyte binding.But modification of BSL did nto influence its bindign with ZP3. These results demonstrated that BSL were bound to sperm and zona pellucida at different sites of the BSL molecule.Binding of sperm and oocyte could be through the BSL molecule which thus acts as a "bridge" between sperm and oocyte. The sperm-oocyte binding was markedly inhibited by the glycopeptide from BSL degradated by pronase E, suggesting that the glycopeptide of BSL may also take part in sperm-oocyte binding.