Li W G, Jaffe R C, Fazleabas A T, Verhage H G
Department of Obstetrics and Gynecology, University of Illinois College of Medicine of Chicago, Illinois 60680.
Biol Reprod. 1991 Apr;44(4):625-31. doi: 10.1095/biolreprod44.4.625.
Sequence analysis of a cDNA clone for the progesterone-dependent protein (PDP) of the cat uterus revealed that PDP may be cathepsin L. This study was undertaken to directly measure the cathepsin L activity in uterine flushings from pregnant and ovariectomized steroid-treated animals in order to confirm that PDP is cathepsin L. Optimum activity toward the substrate Z-Phe-Arg-NMec was observed at a pH of 5-6. Z-Phe-Phe-CHN2, a specific inhibitor of cathepsin L, significantly inhibited the proteolytic activity present in uterine flushings. Immunoabsorption of PDP from uterine flushings obtained from progesterone (P)-treated cats reduced cathepsin L proteolytic activity to levels observed in ovariectomized and estradiol (E2)-treated animals. In E2-primed and E2 + P-treated animals, proteolytic activity in uterine flushings was detectable after 7 days and peaked after 11-13 days of E2 + P treatment. This proteolytic activity was also dramatically increased before implantation (10-12 days after coitus) in pregnant cats. Thus, our data indicate that changes in cathepsin L activity in uterine flushings are correlated with changes in PDP, the uterine protein synthesized and released from the epithelial cells of the deep uterine glands. PDP, via its cathepsin L proteolytic activity, may play a role in the implantation process.
对猫子宫中孕酮依赖性蛋白（PDP）的cDNA克隆进行序列分析显示，PDP可能是组织蛋白酶L。本研究旨在直接测量怀孕和去卵巢并经类固醇处理的动物子宫冲洗液中的组织蛋白酶L活性，以证实PDP就是组织蛋白酶L。在pH为5 - 6时观察到对底物Z - Phe - Arg - NMec的最佳活性。组织蛋白酶L的特异性抑制剂Z - Phe - Phe - CHN2显著抑制了子宫冲洗液中的蛋白水解活性。从经孕酮（P）处理的猫获得的子宫冲洗液中免疫吸附PDP后，组织蛋白酶L的蛋白水解活性降低至去卵巢并经雌二醇（E2）处理的动物中观察到的水平。在经E2预处理和E2 + P处理的动物中，子宫冲洗液中的蛋白水解活性在7天后可检测到，并在E2 + P处理11 - 13天后达到峰值。在怀孕猫的植入前（交配后10 - 12天），这种蛋白水解活性也显著增加。因此，我们的数据表明，子宫冲洗液中组织蛋白酶L活性的变化与PDP的变化相关，PDP是由子宫深部腺体上皮细胞合成并释放的子宫蛋白。PDP通过其组织蛋白酶L的蛋白水解活性，可能在植入过程中发挥作用。
