Characterization of insulin-like growth factor-binding proteins of porcine ovarian follicular fluid.
Characterization of insulin-like growth factor-binding proteins of porcine ovarian follicular fluid.
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猪卵巢卵泡液胰岛素样生长因子结合蛋白的表征。
DOI：
10.1095/biolreprod44.2.315
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发表时间：
1991
影响因子：
3.6
通讯作者：
Hammond,JM
中科院分区：
文献类型：
--
作者：
Mondschein,JS;Etherton,TD;Hammond,JM
通过竞争性配体结合研究、配体印迹和免疫沉淀，我们对猪卵泡液中的胰岛素样生长因子（IGF）结合蛋白（BP）进行了表征。竞争性配体结合研究表明，卵巢 IGFBP 对 IGF-II 的偏好高于 IGF-I。来自 1-3 毫米小卵泡的卵泡液对 IGF 的结合能力几乎是来自 6-10 毫米大卵泡的卵泡液的两倍。猪卵泡液的配体印迹解析了 IGF 结合活性的 5 个主要条带，其表观分子大小为 44、40、34、29 和 22 kDa。 40-44-kDa 条带通过猪 IGFBP-3 抗体进行免疫沉淀，IGFBP-3 是猪血清中 150-kDa 生长激素依赖性 IGF 结合蛋白复合物的酸稳定亚基。 34 kDa 条带通过大鼠 IGFBP-2 抗体进行免疫沉淀，IGFBP-2 是胎鼠血清中发现的主要 IGF 结合蛋白。迄今为止，我们还无法使用任何测试的抗体（包括一组针对人 IGFBP-1（羊水 IGF 结合蛋白）的单克隆抗体）对 29-和 22-kDa 条带进行免疫沉淀。 40-44-kDa 物种 (IGFBP-3) 是主要形式，并且在大卵泡和小卵泡的液体中同样丰富。相比之下，较小的形式，包括 IGFBP-2 以及 29-kDa 和 22-kDa 形式，在小卵泡的液体中明显更为突出。鉴于其他研究表明IGFBP对卵巢细胞功能具有显着影响，卵泡IGFBP可能在卵巢IGF自分泌/旁分泌调节系统中发挥重要作用。
Using competitive ligand-binding studies, ligand blotting, and immunoprecipitation, we have characterized the insulin-like growth factor (IGF)-binding proteins (BPs) of porcine follicular fluid. Competitive ligand-binding studies revealed a preference of ovarian IGFBPs for IGF-II over IGF-I. Follicular fluid from small, 1–3-mm follicles had nearly twice the binding capacity for IGFs as that from large, 6–10-mm follicles. Ligand blots of porcine follicular fluid resolved 5 major bands of IGF-binding activity having apparent molecular sizes of 44, 40, 34, 29, and 22 kDa. The 40–44-kDa bands were immunoprecipitated by an antibody to porcine IGFBP-3, the acid-stable subunit of the 150-kDa growth hormone-dependent IGF-binding protein complex of porcine serum. The 34-kDa band was immunoprecipitated by an antibody to rat IGFBP-2, the major IGF-binding protein found in fetal rat serum. To date we have been unable to immunoprecipitate the 29- and 22-kDa bands with any of the antibodies tested, including a panel of monoclonal antibodies to human IGFBP-1, the amniotic fluid IGF-binding protein. The 40–44-kDa species (IGFBP-3) was the predominant form and was equally abundant in fluid from large and small follicles. In contrast, the smaller forms, including IGFBP-2 and the 29- and 22-kDa forms were significantly more prominent in fluid from small follicles. In view of other studies indicating a significant effect of IGFBPs on ovarian cell function, follicular IGFBPs may play an important role in the IGF autocrine/paracrine regulatory system of the ovary.