Heikinheimo M, Saksela O, Lehtovirta P, Seppälä M, Bohn H
Acta Pathol Microbiol Scand C. 1981 Apr;89(2):139-44. doi: 10.1111/j.1699-0463.1981.tb02677.x.
The synthesis of pregnancy-specific beta-1-glycoprotein (SP1) was studied in human syncytiotrophoblast cultures from first trimester placentas. Incorporation of 35S-methionine into SP1 was demonstrated by immunoprecipitation and polyacrylamide gel electrophoresis. In double diffusion the precipitation line of neosynthesized SP1 gave a reaction of complete immunological identity with maternal serum SP1. By indirect immunofluorescence intracellular SP1 was localised in the perinuclear region of the cells. The average rate of SP1 release into culture fluid was 600 ng/mg protein in 24 hours. On a molar basis the release of SP1 was 10 times less than that of human chorionic gonadotrophin (hCG). Our results demonstrate, for the first time, that cultured human syncytiotrophoblasts synthesis SP1 immunologically indistinguishable from placental SP1.
对来自孕早期胎盘的人合体滋养层细胞培养物中妊娠特异性β-1-糖蛋白（SP1）的合成进行了研究。通过免疫沉淀和聚丙烯酰胺凝胶电泳证实了35S-甲硫氨酸掺入到SP1中。在双向扩散中，新合成的SP1的沉淀线与母体血清SP1产生完全免疫同一性反应。通过间接免疫荧光法，细胞内SP1定位于细胞的核周区域。24小时内SP1释放到培养液中的平均速率为600 ng/mg蛋白质。以摩尔为基础，SP1的释放量比人绒毛膜促性腺激素（hCG）少10倍。我们的结果首次证明，培养的人合体滋养层细胞合成的SP1在免疫上与胎盘SP1无法区分。
