The 220-kDa vitelline coat glycoprotein mediates sperm binding in the polarized egg of Unio elongatulus through O-linked oligosaccharides.
The 220-kDa vitelline coat glycoprotein mediates sperm binding in the polarized egg of Unio elongatulus through O-linked oligosaccharides.
复制标题
220 kDa 卵黄膜糖蛋白通过 O 连接寡糖介导 Unio elongatulus 极化卵子中精子的结合。
作者：
R. Focarelli;F. Rosati
在先前的研究中，我们发现220和180 kDa的两种糖蛋白占从长鳍金枪鱼卵的卵黄膜（VC）溶解的物质的80-90%（Focarelli和Rosati，1993）。通过电洗脱纯化两种糖蛋白，并用于产生相应的多克隆抗体。免疫荧光实验表明，180-kDa的蛋白质种类是无处不在的VC，而220-kDa的蛋白质集中在一个有限的区域的植物极，火山口区域，在那里发生的精卵相互作用。结合试验表明，只有220-kDa的蛋白质与精子相互作用，该蛋白质结合在顶端区域，并引发精子顶体的变化。竞争结合试验表明，O-而不是N-连接的寡糖来自220-kDa的蛋白质竞争与精子的蛋白质的结合，岩藻糖参与220-kDa的蛋白质的配体作用。
In previous studies we found that two glycoproteins of 220 and 180 kDa account for 80-90% of the material dissolved from the vitelline coat (VC) of Unio elongatulus egg (Focarelli and Rosati, 1993). The two glycoproteins were purified by electroelution and used to raise the corresponding polyclonal antibodies. Immunofluorescence experiments showed that the 180-kDa protein species is ubiquitous in the VC, whereas the 220-kDa protein is concentrated in a restricted region of the vegetal pole, the crater region, where the sperm-egg interaction occurs. Binding assays indicated that only the 220-kDa protein interacted with the sperm and that the protein bound in the apical region and triggered acrosomal changes in sperm. Competition binding assays showed that O- and not N-linked oligosaccharides derived from the 220-kDa protein competed with the binding of the protein to sperm and that fucose is involved in the ligand role of the 220-kDa protein.