Kinsey W H, Lennarz W J
J Cell Biol. 1981 Nov;91(2 Pt 1):325-31. doi: 10.1083/jcb.91.2.325.
The role of cell surface glycoproteins of the sea urchin egg in binding sperm has been examined by studying the biological activity of glycopeptides derived from these glycoproteins. Glycopeptides were produced from egg surface glycoproteins by Pronase digestion. After fractionation by gel filtration the glycopeptides were tested for their ability to inhibit the binding of sperm to eggs, presumably by competing with the egg surface glycoproteins for binding sites on the sperm. One glycopeptide fraction with an apparent molecular weight of approximately 6,000 was found to be a potent inhibitor of sperm-egg binding, as well as fertilization, even at nanomolar concentrations. This activity was heat stable and exerted its effect against the sperm and not the egg. Experiments with a radiolabeled form of the glycopeptide fraction directly demonstrated that at least one component of it bound to sperm. Specific binding of the radiolabeled glycopeptide occurred only to acrosome-reacted sperm. Because the isolated glycopeptide fraction has many of the characteristics that one would expect of a biologically active fragment of an egg surface receptor for sperm, these findings are consistent with the idea that one or more glycoconjugates on the surface of the egg are involved in sperm binding.
通过研究源自这些糖蛋白的糖肽的生物活性，对海胆卵细胞表面糖蛋白在结合精子中的作用进行了研究。通过链霉蛋白酶消化从卵表面糖蛋白产生糖肽。经凝胶过滤分级分离后，测试糖肽抑制精子与卵结合的能力，推测是通过与卵表面糖蛋白竞争精子上的结合位点来实现的。发现一种表观分子量约为6000的糖肽级分即使在纳摩尔浓度下也是精子-卵结合以及受精的有效抑制剂。这种活性对热稳定，且作用于精子而非卵。用放射性标记形式的糖肽级分进行的实验直接证明其至少有一个组分与精子结合。放射性标记糖肽的特异性结合仅发生在顶体反应的精子上。由于分离出的糖肽级分具有人们预期的卵表面精子受体生物活性片段的许多特征，这些发现与卵表面一种或多种糖缀合物参与精子结合的观点一致。
