Brown C R, von Glos K I, Jones R
J Cell Biol. 1983 Jan;96(1):256-64. doi: 10.1083/jcb.96.1.256.
Glycoproteins on the plasma membrane of testicular and cauda epididymidal spermatozoa have been labeled with galactose oxidase/NaB [3H]4 and sodium metaperiodate/NaB[3H]4, followed by analysis on SDS polyacrylamide gels. The major glycoprotein labeling on testicular spermatozoa has a molecular weight 110,000 whereas on cauda epididymidal spermatozoa greater than 90% of the radio-label is incorporated into proteins of molecular weight 32,000. These 32,000-mol wt X proteins are homologous with proteins of similar molecular weight purified from the epididymal secretion and which have been shown previously to be synthesized in the caput epididymidis under hormonal control. Immunofluorescence revealed that the 32,000-mol wt proteins are present on the flagellum of mature but not immature spermatozoa and that they have a patchy distribution suggesting that they are mobile within the plane of the membrane. The membrane-bound 32,000-mol wt proteins possess hydrophobic domains as revealed by charge-shift electrophoresis and they also label with a lipophilic photoaffinity probe suggesting that they are in contact with the lipid bilayer. The evidence indicates that there is a considerable reorganization of the molecular structure of the plasma membrane of spermatozoa during maturation in the epididymis and that some of the changes are brought about by a direct interaction with epididymal secretory proteins.
睾丸和附睾尾部精子质膜上的糖蛋白已用半乳糖氧化酶/NaB[3H]4和偏高碘酸钠/NaB[3H]4进行标记，随后在SDS聚丙烯酰胺凝胶上进行分析。睾丸精子上主要的糖蛋白标记物分子量为110,000，而在附睾尾部精子上，超过90%的放射性标记掺入到分子量为32,000的蛋白质中。这些分子量为32,000的X蛋白与从附睾分泌物中纯化的分子量相似的蛋白质同源，并且先前已证明这些蛋白质是在激素控制下于附睾头合成的。免疫荧光显示，分子量为32,000的蛋白质存在于成熟精子而非未成熟精子的鞭毛上，且它们呈斑块状分布，这表明它们在膜平面内是可移动的。电荷转移电泳显示，膜结合的分子量为32,000的蛋白质具有疏水结构域，并且它们也能用亲脂性光亲和探针进行标记，这表明它们与脂质双层接触。证据表明，精子在附睾成熟过程中质膜的分子结构发生了相当大的重组，并且一些变化是由与附睾分泌蛋白的直接相互作用引起的。
