Glabe C G, Lennarz W J
J Cell Biol. 1979 Dec;83(3):595-604. doi: 10.1083/jcb.83.3.595.
Bindin, a protein component of the acrosomal vesicle of sea urchin sperm, has been isolated from Arbacia punctulata and strongylocentrous purpuratus. Using this isolated bindin, we have devised a quantitative assay for bindin-mediated egg agglutination and compared the agglutination of bindin eggs from A. puntulata and S. purpuratus. Bindin- mediated agglutination is species -specific in both species, although a measurable degree of heterotypic interaction is observed. Homotypic bindin-egg interactions differ significantly from heterotypic interactions both in the extent of agglutination and the size of the resulting aggregates. We also provide direct evidence that bindin particles agglutinate eggs by adhering to the surfaces of adjacent eggs. Although the A. punctulata bindin preparation displays the same functional properties and consists of one major polypeptide of the same apparent molecular weight as S. purpuratus bindin, its morphology is very different. Unlike the spherical aggregates observed with S. purpuratus bindin, A punctulata bindin exists as lamellar vesicles and binds significant amounts of phospholipids and Triton X-100, suggesting that it may be tightly associated with the acrosomal membrane. Having defined a number of the basic parameters of bindin-mediated agglutination, we examined the effect of a number of saccharides and glycopeptides on bindin-mediated egg agglutination. Carbohydrate-containing components derived from the egg cell surface by proteolysis were found to inhibit bindin-mediated egg agglutination at low concentrations, but this inhibition is not species specific.
结合蛋白是海胆精子顶体小泡的一种蛋白质成分，已从斑点海胆和紫球海胆中分离出来。利用这种分离出的结合蛋白，我们设计了一种用于结合蛋白介导的卵凝集的定量测定方法，并比较了斑点海胆和紫球海胆的结合蛋白对卵的凝集作用。结合蛋白介导的凝集在这两个物种中都是物种特异性的，尽管观察到了一定程度的异型相互作用。同型结合蛋白与卵的相互作用在凝集程度和形成的聚集体大小方面与异型相互作用有显著差异。我们还提供了直接证据，证明结合蛋白颗粒通过粘附在相邻卵的表面使卵凝集。尽管斑点海胆结合蛋白制剂显示出相同的功能特性，并且由一种与紫球海胆结合蛋白具有相同表观分子量的主要多肽组成，但其形态非常不同。与紫球海胆结合蛋白形成的球形聚集体不同，斑点海胆结合蛋白以层状小泡形式存在，并结合大量磷脂和 Triton X - 100，这表明它可能与顶体膜紧密相关。在确定了结合蛋白介导的凝集的一些基本参数后，我们研究了多种糖类和糖肽对结合蛋白介导的卵凝集的影响。通过蛋白水解从卵细胞表面衍生的含碳水化合物成分在低浓度下可抑制结合蛋白介导的卵凝集，但这种抑制不是物种特异性的。
