Moore A, Penfold L M, Johnson J L, Latchman D S, Moore H D
Institute of Zoology, Zoological Society of London, England.
Mol Reprod Dev. 1993 Mar;34(3):280-91. doi: 10.1002/mrd.1080340308.
An antiserum, designated R4 and raised against denatured hamster acrosomes, was shown to localize specifically to the acrosomal region of hamster, rat, mouse, and human spermatozoa, and to inhibit both hamster and human sperm-oocyte binding in vitro. Following screening of a human testis lambda gt11 cDNA expression library with the antiserum R4, a series of cDNA clones were isolated. One (cDNA 134) was selected based on the ability of the beta-galactosidase fusion protein to inhibit human and hamster sperm-zona binding in vitro. The fusion protein was also shown to inhibit the penetration of zona-free hamster oocytes by human spermatozoa. Sequence analysis revealed that cDNA 134 coded for a portion of a serine protease inhibitor (serpin) closely related to plasma Protein C inhibitor. Sequencing of an additional cDNA clone (261) and Northern blot analysis confirmed that a Protein C inhibitor-like mRNA is synthesised in the human testis. Affinity-purified anti-134 antibody specifically localized to the acrosomal region of both hamster and human sperm. Synthetic peptides corresponding to the conserved core region responsible for the interaction of the serpin with its cognate protease also blocked human sperm-zona binding in vitro. The results suggest that this acrosomally located inhibitor plays an important role in the series of binding events that results in human fertilization.
一种名为R4的抗血清是针对变性仓鼠顶体产生的，它被证明能特异性定位于仓鼠、大鼠、小鼠和人类精子的顶体区域，并在体外抑制仓鼠和人类精子与卵母细胞的结合。用抗血清R4筛选人类睾丸λgt11 cDNA表达文库后，分离出一系列cDNA克隆。基于β-半乳糖苷酶融合蛋白在体外抑制人类和仓鼠精子与透明带结合的能力，选择了其中一个（cDNA 134）。该融合蛋白还被证明能抑制人类精子穿透无透明带的仓鼠卵母细胞。序列分析表明，cDNA 134编码一种丝氨酸蛋白酶抑制剂（serpin）的一部分，与血浆蛋白C抑制剂密切相关。对另一个cDNA克隆（261）的测序和Northern印迹分析证实，人类睾丸中合成了一种类似蛋白C抑制剂的mRNA。亲和纯化的抗134抗体特异性定位于仓鼠和人类精子的顶体区域。与负责serpin与其同源蛋白酶相互作用的保守核心区域对应的合成肽在体外也能阻断人类精子与透明带的结合。结果表明，这种位于顶体的抑制剂在导致人类受精的一系列结合事件中起重要作用。
