Evidence for the presence of high-mannose/hybrid oligosaccharide chain(s) on the mouse ZP2 and ZP3.
Evidence for the presence of high-mannose/hybrid oligosaccharide chain(s) on the mouse ZP2 and ZP3.
复制标题
小鼠 ZP2 和 ZP3 上存在高甘露糖/混合寡糖链的证据。
DOI：
10.1095/biolreprod46.1.93
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发表时间：
1992
影响因子：
3.6
通讯作者：
Orgebin-Crist,MC
中科院分区：
文献类型：
--
作者：
Tulsiani,DR;Nagdas,SK;Cornwall,GA;Orgebin-Crist,MC
该实验室的既往研究已在大鼠、小鼠、仓鼠和人精子的质膜上鉴定出一种新型α-D-甘露糖苷酶[Tulsiani et al. J Cell Biol 1989; 109：1257; Biol Reprod 1990; 42：843]。抑制小鼠精子表面α-D-甘露糖苷酶可抑制精子-卵子体外结合，表明精子酶可能在与小鼠透明质酸（ZP）糖缀合物上的互补分子（可能是含甘露糖的寡糖[OS]链）结合方面具有受体样作用[Cornwall et al. Biol Reprod 1991; 44：913]。在这里报道的研究中，我们证明了高甘露糖/混合型OS的存在下，对小鼠的唾液酸成分。从超数排卵小鼠制备的透明带完整卵，进行放射性碘标记，并通过电泳然后电洗脱分离单独的卵母细胞组分（ZP 1，ZP 2和ZP 3）。纯化的ZP组分，当通过固定化伴刀豆球蛋白A柱色谱分离时，显示出以下结果：1）几乎所有应用于固定化凝集素的ZP 1在柱流通物中洗脱（流出物）级分，且无放射性用α-甲基甘露糖苷洗脱，这表明ZP 1可能不含高甘露糖/杂合OS。2）大量的ZP 2和ZP 3都与固定的凝集素结合，用α-甲基甘露糖苷反复洗脱后，这两种组分的洗脱率分别为16%和8%。3)在凝集素柱层析前，用糖苷内切酶H（一种从N-连接糖蛋白中切割高甘露糖/混合型OS链的内切酶）或刀豆α-D-甘露糖苷酶（一种切割α-连接甘露糖残基的外切酶）处理ZP 2和ZP 3，导致与凝集素结合并用α-甲基甘露糖苷洗脱的放射性量减少。这些结果与ZP 2和ZP 3（但不是ZP 1）都含有高甘露糖/杂合OS单元的可能性一致。这些OS链在精卵相互作用的作用进行了讨论。
Previous studies from this laboratory have identified a novel α-D-mannosidase on plasma membranes of rat, mouse, hamster, and human spermatozoa [Tulsiani et al. J Cell Biol 1989; 109:1257; Biol Reprod 1990; 42:843]. Inhibition of the mouse sperm surface α-D-mannosidase inhibits sperm-egg binding in vitro, suggesting that the sperm enzyme may have a receptor-like role in binding to the complementary molecules (presumably mannose-containing oligosaccharide [OS] chains) on the mouse zona pellucida (ZP) glycoconjugates [Cornwall et al. Biol Reprod 1991; 44:913]. In the studies reported here, we demonstrate the presence of high-mannose/hybrid-type OS on mouse zona components. Zona-intact eggs, prepared from superovulated mice, were radioiodinated, and the individual zona components (ZP1, ZP2, and ZP3) were isolated by electrophoresis followed by electroelution. The purified ZP components, when resolved by immobilized concanavalin A column chromatography, showed the following results: 1) Nearly all of the ZP1 applied to the immobilized lectin eluted in the column flow-through (effluent) fractions, and no radioactivity eluted with α-methyl mannoside, suggesting that ZP1 may not contain high-mannose/hybrid OS. 2) A significant amount of both ZP2 and ZP3 bound to the immobilized lectin, and nearly 16% and 8% of the two components, respectively, were repeatedly eluted with α-methyl mannoside. 3) Treatment of ZP2 and ZP3 with endoglycosidase H (an endoenzyme that cleaves high-mannose/hybrid-type OS chains fromN-linked glycoproteins) or with jack bean α-D-mannosidase (an exo-enzyme that cleaves α-linked mannosyl residues) before the lectin column chromatography resulted in a decreased amount of radioactivity bound to the lectin and eluted with α-methyl mannoside. These results are consistent with the possibility that both ZP2 and ZP3 (but not ZP1) contain high-mannose/hybrid OS units. The role of these OS chains in sperm-egg interaction is discussed.