Boar acrosin digestion of the porcine egg coat, zona pellucida, and rearrangement of the zona proteins.
Boar acrosin digestion of the porcine egg coat, zona pellucida, and rearrangement of the zona proteins.
复制标题
公猪顶体酶消化猪卵外皮、透明带以及透明带蛋白质的重排。
DOI：
10.1093/oxfordjournals.jbchem.a122608
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
T. Tobita
中科院分区：
文献类型：
--
作者：
M. Nakano;Y. Tanaka;T. Kimura;Y. Hatanaka;T. Tobita
用纯化的猪顶体酶消化机械分离的、结构完整的由三个糖蛋白家族（PZP 1 -3）组成的猪透明带，然后用HPLC和/或SDS-PAGE分别分析可溶性和不可溶性组分。在等渗溶液中，PZP 1首先降解，然后是PZP 2，而PZP 3对顶体酶具有很强的抗性，反映了这些家族在顶体结构中的组织。随着蛋白质水解的进行，不溶部分中出现了高分子量产物。这些产物在用β-巯基乙醇处理时崩解。用反相高效液相色谱法将顶体酶增溶的蛋白质分离成7个组分。后者的总产率仅为约5重量%。因此，猪精子顶体酶的切割位点有限。由于五个组分含有比原始蛋白质更具亲水性的肽，这些肽似乎可能存在于蛋白质结构的外表面上。不溶性组分的SDS-PAGE显示，顶体酶在低渗溶液中比在等渗溶液中切割的位点更多。因此，在低渗条件下，可以诱导脊髓内侧区域的结构松弛。然而，在低渗溶液中没有形成高分子量的产物，这表明天然结构的聚碳酸酯是其形成的先决条件。
Mechanically isolated, structurally intact porcine zonae pellucidae composed of three families of glycoproteins (PZP1-3) were digested with purified boar acrosin, and then the solublized and unsolubilized fractions were separately analyzed by HPLC and/or SDS-PAGE. In isotonic solution, PZP1 was first degraded and then PZP2, whereas PZP3 was quite resistant to acrosin, reflecting the organization of these families in the zona structure. As the proteolytic hydrolysis proceeded, high-molecular-weight products appeared in the unsolubilized fraction. These products disintegrated on treatment with beta-mercapto-ethanol. The zona materials solubilized by acrosin were separated into seven fractions by reverse phase HPLC. The total yield of the latter was only about 5% by weight. Thus, limited sites of the porcine zona were cleaved by the homologous sperm acrosin. Since five fractions contained peptides that were more hydrophilic than the original proteins, these peptides seemed likely to be present on the outer surface of the zona structure. SDS-PAGE of the unsolubilized fraction showed that acrosin cleaved the zona at many more sites in hypotonic solution than in isotonic solution. Thus, structural relaxation of the inner region of the zona was indicated to be induced under hypotonic conditions. However, no high-molecular-weight products were formed in hypotonic solution, suggesting that the native architecture of the zona is a prerequisite for their formation.