Biochemical studies of proacrosin and acrosin from hamster cauda epididymal spermatozoa.
Biochemical studies of proacrosin and acrosin from hamster cauda epididymal spermatozoa.
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仓鼠尾附睾精子顶体素原和顶体素的生化研究。
DOI：
10.1095/biolreprod14.4.444
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发表时间：
1976
影响因子：
3.6
通讯作者：
S. Mukerji
中科院分区：
文献类型：
--
作者：
S. Meizel;S. Mukerji
通过酸萃取和Sephadex柱层析，从未洗涤的仓鼠尾附睾精子中获得了部分纯化的原顶胞苷酶原。鼠原顶胞苷（占总顶胞苷活性的92%）和活性顶胞苷（占总顶胞苷活性的8%）一起洗脱，表观分子量为70,000±3000。然而，通过完全“自激活”制备的原顶胞素的表观分子量为41000±3000。仓鼠原顶胞素“自活化”是酶原转化为活性酶的二级自催化过程。“自激活”在pH 8.0时最为迅速，Ca？并被Zn2+抑制。我们前期的研究表明，兔精子原acrosin具有相似的性质，这表明这两种原acrosin的分子性质是相似的。仓鼠交叉蛋白与家兔交叉蛋白具有相似的特性：pH最佳；相对于TAME和BAEE的Km值；对氨基苄胺和大豆胰蛋白酶抑制剂的K′s；和Ca2+的刺激。仓鼠的交叉蛋白也被以下已知的抑制兔交叉蛋白的抑制剂所抑制：利马豆和卵泡样胰蛋白酶抑制剂；合成胰蛋白酶抑制剂TLCK、NPGB和苯并脒；和Zn2 +。TPCK和l -精氨酸对仓鼠和家兔的肌球蛋白无抑制作用。两种顶蛋白的显著差异是：(1)仓鼠顶蛋白不能水解家兔顶蛋白底物BANA；(2)仓鼠和家兔顶蛋白的Vmax BAEE/Vmax TAME比值分别为0.2和2.0。首次证实了仓鼠精子顶蛋白对仓鼠卵透明带的水解作用。摘要
Partially purified proacrosin, the zymogen form of acrosin was obtained from unwashed hamster cauda epididymal spermatozoa by acid extraction and Sephadex column chromatography. Hamster proacrosin (92 percent of the total acrosin actviry) and active acrosin (8 percent of the total activity) were eluted together with an apparent molecular weight of 70,000 ± 3000. However, the acrosin produced by complete "autoactivation" of the proacrosin preparation had an apparent molecular weight of 41,000 ± 3000. Hamster proacrosin "autoactivation" was a second order autocatalytie process typical of zymogen conversion to active enzyme. "Autoactivation" was most rapid at pH 8.0, accelerated by Ca?+ and inhibited by Zn2+. Our earlier studies have shown that rabbit sperm proacrosin had similar properties which suggests that the molecular nature of the two proacrosins is similar. The following properties of hamster acrosin were similar to those of rabbit acrosin: pH optima; Km values with respect to TAME and BAEE; K�'s for p-aminobenzamidine and soybean trypsin inhibitor; and stimulation by Ca2+. Hamster acrosin was also inhibited by the following inhibitors known to inhibit rabbit acrosin: lima bean and ovomucoid trypsin inhibitors; the synthetic trypsin inhibitors TLCK, NPGB and benzamidine; and Zn2+. TPCK and L-arginine did not inhibit hamster or rabbit acrosins. Two striking differences between the two acrosins were: 1) hamster acrosin did not hydrolyze the rabbit acrosin substrate BANA: 2) the Vmax BAEE/Vmax TAME ratios of hamster and rabbit acrosins were 0.2 and 2.0 respectively. The hydrolysis of the hamster egg zona pellucida by hamster sperm acrosin was demonstrated for the first time. ABSTRACT