Seminal vesicle autoantigen, a novel phospholipid-binding protein secreted from luminal epithelium of mouse seminal vesicle, exhibits the ability to suppress mouse sperm motility.
Seminal vesicle autoantigen, a novel phospholipid-binding protein secreted from luminal epithelium of mouse seminal vesicle, exhibits the ability to suppress mouse sperm motility.
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精囊自身抗原是一种由小鼠精囊管腔上皮分泌的新型磷脂结合蛋白，具有抑制小鼠精子活力的能力。
作者：
H. Yen;S. Chu;Y. Chen;Y. Chen
精囊自身抗原（SVA）是一种从小鼠精囊分泌物中纯化的19 kDa糖蛋白。在精囊液中定量为0.9%（w/v）。我们研究了它在附性腺中的分布，表征了它在精子表面的结合位点，并评估了它对精子活力的影响。它免疫定位于组织中的初级和次级褶皱的上皮上。从尾部附睾收集的小鼠精子缺乏SVA。细胞化学研究表明整个细胞上存在SVA结合区域。SVA与精子结合的细胞化学染色强度保持不变，即使当细胞用蛋白酶消化，酸或热在100摄氏度10分钟的预处理。此外，SVA-精子结合可以被抑制分散的精子脂质。用薄层色谱重叠法研究了（125）I-SVA与磷脂相互作用的特异性。放射性标记的蛋白质表现出较强的结合纯化的磷脂酰胆碱和磷脂酰丝氨酸和较弱的结合纯化的鞘磷脂，溶血磷脂酰胆碱和磷脂酰乙醇胺，但不与磷脂酸，溶血磷脂酸或磷脂酰肌醇。从精子中提取的脂质中，SVA显示出与磷脂酰胆碱的强结合，与鞘磷脂和中性脂质的弱结合。用（125）I-SVA进行的SVA-精子结合试验确定IC（50）为（3.89+/-0.65 x10（-5）M（-1）），这与通过将磷脂酰胆碱干扰的SVA荧光数据拟合到修改的Scatchard图估计的表观解离常数（9.10+/-0.02 x10（-5）M（-1））一致。SVA显示出抑制精子活力的能力。用计算机辅助精子测定法在37 ℃、含0.3%SVA的培养液中孵育40 min以上，精子的平均路径速度、直线速度和曲线速度均未检测到。
Seminal vesicle autoantigen (SVA) is a 19 kDa glycoprotein purified from mouse seminal vesicle secretion. It was quantified to be 0.9% (w/v) in the seminal vesicle fluid. We examined its distribution in the accessory sexual gland, characterized its binding sites on the sperm surface and assessed its effect on sperm motility. It was immunolocalized on the epithelium of the primary and secondary folds in the tissue. Mouse spermatozoa collected from caudal epididymis were devoid of SVA. A cytochemical study illustrated the presence of SVA-binding region on the entire cells. The cytochemical staining intensity for the binding of SVA to spermatozoa remained even when the cells were pretreated with protease digestion, acid or heat at 100 degrees C for 10 min. Moreover, the SVA-sperm binding could be inhibited by the dispersed sperm lipid. The specificity of interaction between (125)I-SVA and phospholipids was studied by TLC overlay techniques. The radiolabelled protein showed strong binding to purified phosphatidylcholine and phosphatidylserine and weak binding to purified sphingomyelin, lysophosphatidylcholine and phosphatidylethanolamine, but did not interact with phosphatidic acid, lysophosphatidic acid or phosphatidylinositol. Among the lipids extracted from spermatozoa, SVA showed strong binding to phosphatidylcholine and weak binding to sphingomyelin and neutral lipids. The assay for SVA-sperm binding with (125)I-SVA determined the IC(50) as being (3.89+/-0.65)x10(-5) M(-1), which is compatible with an apparent dissociation constant of (9.10+/-0.02)x10(-5) M(-1) estimated by fitting the data of phosphatidylcholine-perturbed SVA fluorescence to a modified Scatchard plot. SVA showed an ability to suppress sperm motility. The average path velocity, straight-line velocity and curvilinear velocity of sperm were not detectable by computer-assisted sperm assay after incubation of the cells in the presence of 0.3% SVA at 37 degrees C for more than 40 min.