Koistinen R, Angervo M, Leinonen P, Seppälä M
Department I of Obstetrics and Gynecology, Helsinki University Central Hospital, Finland.
Growth Regul. 1993 Mar;3(1):34-7.
During purification, insulin-like growth factor binding protein-1 from amniotic fluid was separated into five different peaks by anion exchange chromatography. These peaks represent differently phosphorylated forms of IGFBP-1. The major peak (peak 1) is non-phosphorylated. Peaks 3, 4, and 5 are more phosphorylated and, in native polyacrylamide gel electrophoresis (PAGE), they migrate faster than peaks 1 and 2. The more phosphorylated forms have higher IGF-I-binding affinity. Both dephosphorylated and phosphorylated peaks enhanced IGF-I stimulated DNA-synthesis in fetal skin fibroblast cell culture. They, however, inhibited the binding of IGF-I to the same cells. The phosphorylation of IGFBP-1 was changed during pregnancy. In decidua and in amniotic fluid the degree of phosphorylation increased from early to late pregnancy, as indicated by faster mobility of IGFBP-1 in native PAGE and increased relative amount of the more phosphorylated peaks in anion exchange chromatography. Human ovarian follicular fluid, culture media from human granulosa cells and endometrial adenocarcinoma cells (HEC-1-B) consisted mostly of the non-phosphorylated form of IGFBP-1.
在纯化过程中，羊水来源的胰岛素样生长因子结合蛋白-1通过阴离子交换色谱法被分离成五个不同的峰。这些峰代表了IGFBP-1的不同磷酸化形式。主要峰（峰1）是非磷酸化的。峰3、峰4和峰5的磷酸化程度更高，在天然聚丙烯酰胺凝胶电泳（PAGE）中，它们的迁移速度比峰1和峰2快。磷酸化程度越高的形式具有更高的IGF-I结合亲和力。去磷酸化峰和磷酸化峰均增强了胎儿皮肤成纤维细胞培养中IGF-I刺激的DNA合成。然而，它们抑制了IGF-I与相同细胞的结合。在孕期，IGFBP-1的磷酸化发生了变化。在蜕膜和羊水中，磷酸化程度从妊娠早期到晚期增加，这通过IGFBP-1在天然PAGE中的更快迁移以及阴离子交换色谱中磷酸化程度更高的峰的相对量增加得以体现。人卵巢卵泡液、人颗粒细胞和子宫内膜腺癌细胞（HEC-1-B）的培养基主要由非磷酸化形式的IGFBP-1组成。
