Release of ovoperoxidase from sea urchin eggs hardens the fertilization membrane with tyrosine crosslinks.
Release of ovoperoxidase from sea urchin eggs hardens the fertilization membrane with tyrosine crosslinks.
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海胆卵释放的卵过氧化物酶通过酪氨酸交联使受精膜硬化。
DOI：
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发表时间：
1977
影响因子：
11.1
通讯作者：
B. Shapiro
中科院分区：
文献类型：
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作者：
C. Foerder;B. Shapiro
受精的一个特征是卵黄层的改变，通过从卵中释放的成分，产生升高的、共价交联的、硬的、不溶性的受精膜。以下证据表明，交联和硬化是由二和三酪氨酰残基的产生引起的，通过在过氧化物酶存在下氧化蛋白质结合的酪氨酰残基。受精膜的硬化，如其在50 mM二硫苏糖醇中溶解度的损失所证明的，被已知抑制许多过氧化物酶的化合物抑制。一种过氧化物酶，这里称为卵过氧化物酶，在受精时从卵中释放出来。这种酶被抑制硬化的相同化合物抑制，并且浓度相似。卵过氧化物酶和硬化反应的抑制剂包括KCN、3-氨基-1，2，4-三唑、NaN（3）、苯肼、K（4）Fe（CN）（6）、亚硫酸钠和甘氨酸乙酯。此外，酪胺和N-乙酰酪氨酸都抑制硬化，但O-甲基酪氨酸不。二酪氨酰和三酪氨酰残基存在于分离的硬化受精膜的酸水解产物中。已通过磷酸纤维素柱色谱法、薄层色谱法和氨基酸分析鉴定了这些残留物。氨基酸数据已用于估计每55，000道尔顿蛋白质中有一个二酪氨酸交联。我们认为，通过催化酪氨酰残基的交联，卵过氧化物酶导致产生硬受精膜，阻止额外的精子进入。由于过氧化物酶是杀精子的，这种酶的第二个功能可能是杀死受精卵附近的精子。
One feature of fertilization is the alteration of the vitelline layer, by components released from the egg, to produce an elevated, covalently crosslinked, hard, insoluble, fertilization membrane. The following evidence indicates that crosslinking and hardening are caused by the production of diand trityrosyl residues, by oxidation of protein-bound tyrosyl residues in the presence of a peroxidase. Hardening of the fertilization membrane, as evidenced by its loss of solubility in 50 mM dithiothreitol, is inhibited by compounds known to inhibit many peroxidases. A peroxidase, here called the ovoperoxidase, is released from eggs at fertilization. This enzyme is inhibited by the same compounds that inhibit hardening and at similar concentrations. Inhibitors of the ovoperoxidase and the hardening reaction include KCN, 3-amino-1,2,4-triazole, NaN(3), phenylhydrazine, K(4)Fe(CN)(6), sodium sulfite, and glycine ethyl ester. In addition, tyramine and N-acetyltyrosine both inhibit hardening, but O-methyltyrosine does not. Dityrosyl and trityrosyl residues are found in acid hydrolysates of isolated, hardened fertilization membranes. These residues have been identified by cellulose phosphate column chromatography, thin-layer chromatography, and amino acid analysis. The amino acid data have been used to estimate that there is one dityrosine crosslink per 55,000 daltons of protein. We suggest that, by catalyzing the crosslinking of tyrosyl residues, the ovoperoxidase leads to the production of a hard fertilization membrane that blocks the entry of additional sperm. Because peroxidases are spermicidal, a secondary function of the enzyme could be to kill sperm in the vicinity of the fertilized egg.