Effects of acrosin inhibitors on the soluble and membrane-bound forms of ram acrosin, and a reappraisal of the role of the enzyme in fertilization.
Effects of acrosin inhibitors on the soluble and membrane-bound forms of ram acrosin, and a reappraisal of the role of the enzyme in fertilization.
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顶体素抑制剂对公羊顶体素可溶性和膜结合形式的影响，以及该酶在受精中作用的重新评估。
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
E. Hartree
中科院分区：
文献类型：
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作者：
C. Brown;E. Hartree
当剥离的公羊精子悬浮在弱缓冲的0.25M蔗糖中时，顶体酶仍然与精子头的顶体膜结合。含有CaCl2的介质使酶完全增溶。在含蔗糖的Tris HCl(pH 8.2)中，研究了顶体酶抑制剂对可溶性酶和结合酶的影响。以去皮精子作为结合顶体酶的制备方法。Trasylol(库尼茨碱性胰酶抑制剂)对结合的胃泌素的作用比对可溶性顶体酶的作用更强，而大豆胰酶抑制剂对可溶性顶体酶的作用更强。在0.5-2.0µM浓度范围内，从绵羊顶体和精浆中分离得到的抑制物对可溶性顶体酶有抑制作用，而对结合顶体酶的抑制作用不明显。然而，结合的顶体酶对高浓度的顶体抑制物敏感。对氨基苯甲胺和Tos-Lys-CH2Cl对这两种形式的顶体酶的抑制程度大致相同。有人认为，膜结合的顶体酶是穿透透明带的形式，顶体酶抑制剂的作用是抑制可溶性顶体酶对哺乳动物卵子的抗生育作用。这一假说得到以下结果的支持：1)用顶体酶抑制剂处理的兔精子受精能力受损的研究结果；2)顶体酶和牛胰酶溶液对仓鼠卵子的抗生育作用；3)本文的结果。
When denuded ram spermatozoa were suspended in weakly buffered 0.25M sucrose, the acrosin remained bound to the acrosomal membranes of the sperm heads. Media containing CaCl2 caused complete solubilization of the enzyme. Effects of acrosin inhibitors on soluble and bound enzyme were studied in Tris HCl(pH 8.2) containing sucrose. Denuded spermatozoa were used as a preparation of bound acrosin. Trasylol (Kunitz basic pancreatic trypsin inhibitor) acted more strongly on bound scrosin than on soluble acrosin, but soya-bean trypsin inhibitor acted more strongly on soluble acrosin. At concentrations 0.5 - 2.0muM, the inhibitors isolated from ram acrosomes and from ram seminal plasma inhibited soluble acrosin but had negligible effects on bound acrosin. However, bound acrosin was sensitive to high concentrations of the acrosomal inhibitor. The two forms of acrosin were inhibited to about the same degree by p-aminobenzamidine and also by Tos-Lys-CH2Cl. It is proposed that membrane-bound acrosin is the form that functions in penetration of the zona pellucida, and that a role for acrosin inhibitors is suppression of an antifertility effect of soluble acrosin on mammalian eggs. This hypothesis is supported by 1) the results of work on the impaired fertilizing capacity of rabbit spermatozoa that have been treated with acrosin inhibitors, 2) the anti-fertility effects on hamster eggs of solutions of acrosin and of bovine trypsin, and 3) the results in this paper.