The fucose sulfate polymer of egg jelly binds to sperm REJ and is the inducer of the sea urchin sperm acrosome reaction.
The fucose sulfate polymer of egg jelly binds to sperm REJ and is the inducer of the sea urchin sperm acrosome reaction.
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卵果冻的岩藻糖硫酸聚合物与精子 REJ 结合，是海胆精子顶体反应的诱导剂。
DOI：
10.1006/dbio.1997.8729
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发表时间：
1997
影响因子：
2.7
通讯作者：
Moy,GW
中科院分区：
文献类型：
--
作者：
Vacquier,VD;Moy,GW
海胆精子细胞是研究配体介导的胞吐作用的有利模型。可以大量获得精子并诱导其以高度同步的方式进行顶体囊泡的胞吐作用。在海胆受精过程中，卵果冻 (EJ) 会触发精子顶体反应 (AR)，这是精子与卵子结合和融合所必需的。 AR 诱导剂的确切生化性质存在不确定性。进行以下研究是为了阐明诱导剂的性质。在 SDS-PAGE 凝胶上分析来自雌性个体（Strongylocentrotus purpuratus）的 EJ。每个雌性都有独特的 EJ 大分子组成，但所有雌性都拥有先前描述的岩藻糖硫酸聚合物 (FSP)。发现了 FSP 的两种电泳同种型； 87% 的女性只有一种同型，13% 则两种都有。两种 FSP 同种型均与从精子中纯化的 REJ 蛋白（卵胶受体）结合。两种 FSP 同种型在诱导 AR 方面几乎具有相同的效力。 EJ 通过 DEAE 色谱法在 6 M 尿素/4% β-巯基乙醇中进行分级。所有 AR 诱导活性均与 FSP 共洗脱。通过胰蛋白酶消化和透析纯化的 FSP 在诱导 AR 方面的活性是未经胰蛋白酶消化的对照的两倍。 EJ用蛋白酶K消化，在去污剂和β-巯基乙醇中煮沸，并进行蔗糖密度梯度沉降。 FSP 和 AR 活性具有重叠的沉降模式。纯化的 FSP 没有相关的肽成分。来自个体男性的精子在纯化 FSP 诱导 AR 的浓度依赖性方面有所不同。数据表明，之前被认为充当 AR 诱导剂的 138/82 kDa EJ 糖蛋白似乎并不参与触发 AR。这些数据与 FSP 是该海胆物种 AR 的唯一诱导剂的假设一致。
The sea urchin sperm cell is an advantageous model for studying ligand-mediated exocytosis. Sperm can be obtained in vast quantities and induced to undergo exocytosis of the acrosomal vesicle with great synchrony. During sea urchin fertilization, egg jelly (EJ) triggers the sperm acrosome reaction (AR) which is required for sperm binding and fusion with the egg. Uncertainty exists as to the exact biochemical nature of the AR inducer. The following study was performed in an attempt to clarify the nature of the inducer. EJ from individual females (Strongylocentrotus purpuratus) was analyzed on SDS–PAGE gels. Each female had a unique composition of EJ macromolecules, but all females possessed the previously described fucose sulfate polymer (FSP). Two electrophoretic isotypes of FSP were discovered; 87% of females had only one isotype and 13% had both. Both FSP isotypes bound to the REJ protein (receptor for egg jelly) purified from sperm. The two FSP isotypes had almost equal potency in inducing the AR. EJ was fractionated by DEAE chromatography in 6 M urea/4% β-mercaptoethanol. All AR-inducing activity coeluted with FSP. FSP, purified by trypsin digestion followed by dialysis, was twice as active as the non-trypsin-digested control at inducing the AR. EJ was digested with proteinase K, boiled in detergent and β-mercaptoethanol, and subjected to sucrose density gradient sedimentation. The FSP and AR activity had superimposable sedimentation patterns. Purified FSP had no associated peptide component. Sperm from individual males differed in the concentration dependency of purified FSP to induce the AR. The data indicate that the 138/82 kDa EJ glycoproteins, previously thought to act as AR inducers, do not appear to be involved in triggering the AR. The data are consistent with the hypothesis that FSP is the only inducer of the AR of this sea urchin species.