MAJOR PROTEINS OF BOVINE SEMINAL-VESICLES BIND TO SPERMATOZOA
MAJOR PROTEINS OF BOVINE SEMINAL-VESICLES BIND TO SPERMATOZOA
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DOI：
10.1095/biolreprod50.1.27
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发表时间：
1994-01-01
影响因子：
3.6
通讯作者：
DESNOYERS, L
中科院分区：
文献类型：
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作者：
MANJUNATH, P;CHANDONNET, L;DESNOYERS, L
牛精囊合成一个密切相关的蛋白质家族，即BSP-A1、BSP-A2、BSP-A3和BSP-30-kDa（统称为BSP蛋白）。最近，我们发现这些蛋白质特异性结合胆碱磷脂。由于这类磷脂是精子膜的主要磷脂组分，我们研究了BSP蛋白与精子的结合。针对纯化的BSP蛋白在兔中提出的多克隆抗体被用来检测这些抗原在牛附睾和射出的精子，以及在牛精浆。通过使用各种技术，即，表面标记，然后免疫沉淀和免疫印迹，从附睾尾与射出的精子的精子的比较表明，附睾精子没有BSP蛋白，而射出的精子具有膜结合的BSP蛋白。通过间接免疫荧光技术，公牛射出精子的免疫反应仅限于中段、顶体和顶体后区，而附睾精子表面未发现特异性免疫染色。精子表面标记的BSP蛋白不能用含有高盐浓度（1 M NaCl）的缓冲液置换，但可以用磷酸胆碱（单独或与尿素结合）特异性置换。这些数据表明，BSP蛋白是精囊分泌产物，在射精时结合到精子表面。
Bovine seminal vesicles synthesize a family of closely related proteins, namely BSP-A1, BSP-A2, BSP-A3, and BSP-30-kDa (collectively called BSP proteins). Recently, we showed that these proteins bind specifically to choline phospholipids. Since this class of phospholipids is the major phospholipid fraction of the spermatozoan membrane, we investigated the binding of BSP proteins to spermatozoa. Polyclonal antibodies against purified BSP proteins raised in rabbits were used to detect these antigens in bovine epididymal and ejaculated spermatozoa as well as in bovine seminal plasma. Comparison of spermatozoa taken from the caudae epididymides with ejaculated spermatozoa through use of various techniques, namely, surface labeling followed by immunoprecipitation and immunoblotting, showed that epididymal spermatozoa are devoid of BSP proteins whereas ejaculated spermatozoa possess membrane-bound BSP proteins. Through use of the indirect immunofluorescence technique, the ejaculated spermatozoa of bull were characterized by an immunoreaction restricted to the midpiece, acrosome, and postacrosomal region, but no specific immunostaining could be found on the surface of epididymal spermatozoa. Surface-labeled BSP proteins on spermatozoa could not be displaced with buffers containing high salt concentration (1 M NaCl), but could be displaced specifically with phosphorylcholine (alone or in combination with urea). The data indicate that the BSP proteins that are secretory products of the seminal vesicles bind to the sperm surface upon ejaculation.