Localization of wheat germ agglutinin and antibody binding sites on the plasma membranes of sea urchin sperm heads as revealed by label-fracture and fracture-flip.
Localization of wheat germ agglutinin and antibody binding sites on the plasma membranes of sea urchin sperm heads as revealed by label-fracture and fracture-flip.
复制标题
通过标签断裂和断裂翻转揭示海胆精子头质膜上小麦胚芽凝集素和抗体结合位点的定位。
DOI：
10.1002/mrd.1080280414
复制
发表时间：
1991
影响因子：
2.5
通讯作者：
Nishioka,D
中科院分区：
文献类型：
--
作者：
Shen,RL;Ward,RD;PintodaSilva,P;Nishioka,D
冷冻断裂电子显微镜显示，膜内颗粒集中在一个带包围的后部的顶体的球海胆purpuratussperm。两种胶体金标记方法，标签断裂和复制断裂翻转，被用来显示植物凝集素小麦胚芽凝集素，它识别210 kDa的精子表面糖蛋白，结合到这个膜内颗粒的局部带。单克隆抗体J18/2也识别210 kDa表面糖蛋白，在本研究中观察到约20%的精子中显示了这种局部结合。大多数精子显示单克隆抗体J18/2的受体位点的均匀分布。由于麦胚凝集素和单克隆抗体J18/2已知可凝集Strongylocentrotus purpuratussperm，但不凝集另一种海胆Lytechinus pictus的精子，因此对后者进行了类似的测定。麦胚凝集素和单克隆抗体J18/2受体在紫球海胆精子中的顶体定位与210 kDa表面糖蛋白参与卵冻诱导的精子顶体反应一致。用麦胚凝集素和单克隆抗体J18/2对薄切片进行低温包埋后标记，显示在红球海胆精子顶体囊泡内的标记浓度，表明存在210 kDa糖蛋白的细胞内储存位点。
Freeze‐fracture electron microscopy reveals that intramembrane particles are concentrated in a band encircling the posterior portion of the acrosome ofStrongylocentrotus purpuratussperm. Two colloidal gold labeling methods, label‐fracture and replicastaining fracture‐flip, were employed to show that the plant lectin wheat germ agglutinin, which recognizes a 210 kDa sperm surface glycoprotein, binds to this localized band of intramembrane particles. Monoclonal antibody J18/2, which also recognizes the 210 kDa surface glycoprotein, shows this localized binding in ≈20% of the sperm observed in this study. The majority of sperm displayed a uniform distribution of receptor sites for monoclonal antibody J18/2. Since wheat germ agglutinin and monoclonal antibody J18/2 are known to agglutinateStrongylocentrotus purpuratussperm but not sperm of another sea urchin,Lytechinus pictus, similar determinations were made for the latter species.Lytechinus pictussperm are not labeled with wheat germ agglutinin and are only sparsely labeled with monoclonal antibody J18/2. The acrosomal localizations of wheat germ agglutinin and monoclonal antibody J18/2 receptors inStrongylocentrotus purpuratussperm are consistent with the involvement of the 210 kDa surface glycoprotein in an egg jelly‐induced sperm acrosome reaction. Low‐temperature post‐embed labeling of thin sections with wheat germ agglutinin and monoclonal antibody J18/2 show concentrations of label within the acrosomal vesicle ofStrongylocentrotus purpuratussperm, suggesting the presence of an intracellular storage site for the 210 kDa glycoprotein.