目的： 制备人精浆蛋白特异性单链抗体，并检测其生物活性与靶向性。方法： 应用快速翻译系统（RTS）表达γ-精浆蛋白特异性单链抗体，制备E4B7ScFv肽段和纳米颗粒偶联物，应用免疫沉淀反应、Western Blotting法、免疫荧光染色分析和细胞实验，研究该抗体进入前列腺癌细胞的活性。结果：成功地制备了抗γ-精浆蛋白特异性单链抗体纳米颗粒偶联物。该抗体可与前列腺癌细胞特异性结合，并可在15 min内将纳米磁珠带入前列腺癌细胞内，进入癌细胞的磁球数量随着细胞培养时间的延长而增多，对照实验显示该偶联物不能进入其它组织肿瘤细胞。结论：制备的抗γ-精浆蛋白特异性单链抗体生物活性与靶向性均较好，在前列腺癌的早期核磁共振显像诊断与靶向治疗上具有潜在的应用价值。

Objective: To prepare the single-chain antibody of γ-seminoprotein and to determine its biological activity and specific targeting ability. Methods: Rapid translation system was used to express single-chain anti-γ-seminoprotein antibody; immunoprecipitation, Western blotting, immunofluorescent staining and cellular test were used to investigate the activity and the efficiency of the antibody after entering into prostate cancer cells. Results: The single-chain anti-γ-seminoprotein antibody was successfully prepared, which could specifically bind with the prostate cells and could bring magnetic beads into prostate cancer cells within 15 min, and the amount of magnetic beads in prostate cancer cells increased as the culture time prolonged. Control study showed that the antibody conjugated magnetic beads could not enter other normal cells or tumors. Conclusion: The prepared single-chain anti-γ-seminoprotein antibody has satisfactory biological activity and targeting ability, which makes it promising for the early NMR detection and targeting therapy of prostate cancer.

国家重大基础研究发展“973”规划课题 （No.2005CB724300-G);国家自然科学基金资助项目（No.30470511)