Structure and function of asterosaps, sperm-activating peptides from the jelly coat of starfish eggs
Structure and function of asterosaps, sperm-activating peptides from the jelly coat of starfish eggs
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DOI：
10.1017/s0967199400003154
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发表时间：
1996-08-01
期刊：
影响因子：
1.7
通讯作者：
Hoshi, M
中科院分区：
文献类型：
--
作者：
Nishigaki, T;Chiba, K;Hoshi, M
海星卵的果冻层具有激活同源精子并诱导顶体反应的能力。我们从海星 Asterias amurensis 的卵胶中分离出 12 种精子激活肽 (SAP)。通过序列分析和电喷雾电离质谱法对 11 种 SAP 进行了结构鉴定。它们都是富含谷氨酰胺的四十三肽，Cys(8) 和 Cys(32) 之间具有分子内二硫键。它们比海胆 SAP 大得多，并且与已知蛋白质没有任何显着的序列相似性。因此，我们将它们统称为星月。观察到星形树的结构多样性的氨基末端区域对于它们的活性并不重要，而二硫键是必需的。 Asterosaps 本身不会诱导顶体反应，但能够与名为 ARTS 的蛋冻糖复合物结合诱导顶体反应。此外，抗asterosap兔抗体显着降低了果冻溶液的顶体反应诱导活性，并且通过添加过量的asterosap恢复了活性。这些结果支持我们的假设，即 SAP 的主要生理作用是与其他两种胶冻成分 ARTS 和 Co-ARIS 合作诱导顶体反应。
Jelly coat of starfish eggs has the capacity to activate homologous spermatozoa and induce the acrosome reaction. We have isolated 12 sperm-activating peptides (SAPs) from the egg jelly of the starfish, Asterias amurensis. Eleven SAPs were structurally identified by sequence analysis and electrospray ionisation mass spectrometry. All of them are glutamine-rich tetratriacontapeptides with an intramolecular disulphide Linkage between Cys(8) and Cys(32). They are much larger than sea urchin SAPs and do not show any significant sequence similarities to known proteins. Thus we have collectively named them asterosaps. The amino terminal region, where structural diversity of asterosaps is observed, is not important for their activity, whereas the disulphide Linkage is essential. Asterosaps do not induce the acrosome reaction by themselves, but are able to induce the acrosome reaction in combination with an egg jelly glycoconjugate named ARTS. Furthermore, anti-asterosap rabbit antibody significantly decreased the acrosome reaction-inducing activity of the jelly solution and the activity was restored by addition of excess asterosap. These results support our hypothesis that the main physiological role of SAPs is the induction of the acrosome reaction in cooperation with two other jelly components, ARTS and Co-ARIS.