Species-specific sequences of abalone lysin, the sperm protein that creates a hole in the egg envelope.
Species-specific sequences of abalone lysin, the sperm protein that creates a hole in the egg envelope.
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鲍鱼溶素的物种特异性序列，这是一种在卵子包膜上形成孔洞的精子蛋白。
DOI：
10.1073/pnas.87.15.5792
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发表时间：
1990
影响因子：
11.1
通讯作者：
Stout,CD
中科院分区：
文献类型：
--
作者：
Vacquier,VD;Carner,KR;Stout,CD
鲍鱼卵被包裹在坚硬的卵黄膜中，精子必须通过卵黄膜才能到达卵细胞膜。鲍鱼精子具有一种叫做溶酶的顶体蛋白，它通过非酶机制在卵黄膜上形成一个洞。来自两种鲍鱼的溶酶素，被称为粉红色和红色，它们共享相同的栖息地，在分离卵囊的溶解中表现出物种特异性。粉色和红色鲍鱼溶酶cdna的克隆和测序显示转录物长度约为660个核苷酸。465（粉色）和462（红色）核苷酸的开放阅读框显示出13%的差异。聚(A)尾部前的3'非翻译区有170（粉色）和165（红色）个核苷酸长，彼此相差约7%。蛋白质序列显示两种溶酶的18个氨基酸几乎相同的信号序列。粉鲍鱼成熟蛋白为137个氨基酸，红鲍鱼成熟蛋白为136个氨基酸；这两种成熟的溶酶素在137个氨基酸中有29个不同（21%）。最易变化的区域可能解释了溶酶的物种特异性，是在NH2端，在那里15个氨基酸中有11个在两个物种之间不同。二级结构预测表明两种溶酶都含有四个同源的两亲性α -螺旋。
Abalone eggs are contained within a rigid, elevated vitelline envelope through which the sperm must pass before reaching the egg cell membrane. Abalone spermatozoa possess an acrosomal protein called lysin that creates a hole in the egg vitelline envelope by a nonenzymatic mechanism. Lysins from two species of abalone, termed pink and red, which share the same habitat, exhibit species specificity in the dissolution of isolated egg envelopes. Cloning and sequencing the cDNAs for pink and red abalone lysins reveal transcript lengths of approximately 660 nucleotides. The open reading frames of 465 (pink) and 462 (red) nucleotides show a 13% difference. The 3' untranslated regions before the poly(A) tails are 170 (pink) and 165 (red) nucleotides long and differ from each other by about 7%. The protein sequences show nearly identical signal sequences of 18 amino acids for both lysins. The mature protein is 137 amino acids in the pink abalone and 136 in the red abalone; the two mature lysins differ in 29 of 137 amino acids (21%). The most variable region, which may account for lysin's species specificity, is at the NH2 terminus, where 11 of the 15 amino acids differ between the two species. Predictions of secondary structure indicate that both lysins contain four homologous amphiphilic alpha-helices.