ISOLATION AND CHARACTERIZATION OF A NOVEL HUMAN SPERM ANTIGEN (H-SP-1)

用人精子特异性抗血清从人睾丸cDNA文库中筛选出一个人精子抗原基因(h-SP-1)。序列分析表明，该基因全长2170个碱基，与人突触素基因有45%的同源性，被认为在神经末梢突触小泡的钙依赖信号转导中起重要作用。对h-sp-1基因的氨基酸序列分析表明，该基因编码259个氨基酸，包括4个亲水区和4个疏水区。这表明h-SP-1基因编码的分子可能是一种跨膜蛋白，与突触素一样具有四个跨膜区域。用合成的h-SP-1多肽(No174-198)免疫兔和小鼠，制备抗血清，对hSP-1基因编码的分子进行鉴定。通过间接免疫荧光染色，得到染色的抗血清固定人精子头部。纯化的抗h-SP-1抗体对人精子对去透明带仓鼠卵子的穿透试验有抑制作用。然而，它们没有表现出任何精子固定和凝集活性。这些结果提示h-SP-1基因编码的分子可能在精子-卵子相互作用中起重要作用。

We isolated a human sperm antigen gene (h-sp-1) by screening from human testis cDNA library with human sperm specific antisera. The sequence analysis of the h-sp-1 gene indicated that it contained 2170 bp and had 45% homology to human synaptophysin gene, which was considered to play a crucial role in calcium dependent signal transduction in synaptic vesicles in the terminal end of nerves. The analysis of the deduced amino acids from the h-sp-1 gene showed that it encoded 259 amino acids containing four hydrophilic regions and four hydrophobic regions. This indicated that the molecules encoded by the h-sp-1 gene might be a transmembrane protein with four membrane spanning regions like the synaptophysin. In order to characterize the molecules encoded by the hsp-1 gene, the antisera were generated by immunizing rabbits and mice with synthetic polypeptides (No174-198) based on the h-sp-1 gene. The resultant antisera stained fixed human sperm head by indirect immunofluorescence staining. The purified anti-h-sp-1 antibodies showed the inhibitory effect on human sperm penetration assay into zona-free hamster eggs. However they did not show any sperm immobilizing and agglutinating activities. These results suggested that the molecules encoded by the h-sp-1 gene might play an important role in the sperm-egg interaction.