Koistinen R, Angervo M, Leinonen P, Hakala T, Seppälä M
Department I of Obstetrics and Gynaecology, Helsinki University Central Hospital, Finland.
Clin Chim Acta. 1993 Jun 16;215(2):189-99. doi: 10.1016/0009-8981(93)90125-n.
Different fractions of insulin-like growth factor-binding protein-1 (IGFBP-1) from anion exchange chromatography represent differently phosphorylated forms as demonstrated by protein kinase and alkaline phosphatase treatments. The major fraction is non-phosphorylated. Three minor fractions are more phosphorylated and, in native polyacrylamide gel electrophoresis (PAGE), they migrate faster than the major fractions. We studied the changes in phosphorylation of decidual and amniotic fluid IGFBP-1 during pregnancy. Both 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 phosphorylated forms in anion exchange chromatography. The more phosphorylated forms had higher IGF-binding affinity than the less phosphorylated forms. As the degree of phosphorylation of IGFBP-1 is highest in full term decidua it is likely that the inhibitory role of IGFBP-1 is accentuated in the end of pregnancy.
来自阴离子交换色谱的胰岛素样生长因子结合蛋白-1（IGFBP-1）的不同组分代表不同的磷酸化形式，这通过蛋白激酶和碱性磷酸酶处理得以证明。主要组分是非磷酸化的。三个次要组分磷酸化程度更高，并且在天然聚丙烯酰胺凝胶电泳（PAGE）中，它们的迁移速度比主要组分快。我们研究了孕期蜕膜和羊水IGFBP-1磷酸化的变化。在蜕膜和羊水中，磷酸化程度从妊娠早期到晚期均增加，这通过天然PAGE中IGFBP-1更快的迁移速度以及阴离子交换色谱中磷酸化形式相对量的增加得以表明。磷酸化程度更高的形式比磷酸化程度较低的形式具有更高的IGF结合亲和力。由于IGFBP-1的磷酸化程度在足月蜕膜中最高，因此IGFBP-1的抑制作用在妊娠末期可能会增强。
