van Dijk H P, Kroos M J, Starreveld J S, van Eijk H G, Tang S P, Song D X, Muller-Eberhard U
Department of Chemical Pathology, Erasmus Universiteit Rotterdam, The Netherlands.
Biochem J. 1995 May 1;307 ( Pt 3)(Pt 3):669-72. doi: 10.1042/bj3070669.
The expression of cell-surface haemopexin (Hx) receptors on human cytotrophoblasts was assessed by using four different Hx species purified from plasma: human Hx isolated by wheatgerm-affinity chromatography, human Hx isolated by haem-agarose-affinity chromatography and rabbit and rat Hx, also isolated by haem-agarose-affinity chromatography. About 3500-7000 high-affinity (Kd 0.34-0.85 nM) receptors per cell were measured by Scatchard-type analysis at 4 degrees C using human (species obtained by both methods) or rabbit 125I-labelled haem-Hx. Measured simultaneously, transferrin receptor number and affinity were 40,000/cell and 0.83 nM respectively. In contrast with transferrin receptors, the number of Hx receptors did not increase during 24 h in cytotrophoblast culture. Rat Hx showed no specific binding to human Hx receptors in cytotrophoblast cultures.
利用从血浆中纯化得到的四种不同血红素结合蛋白（Hx），评估人细胞滋养层细胞表面Hx受体的表达：通过麦胚亲和层析法分离得到的人Hx、通过血红素琼脂糖亲和层析法分离得到的人Hx以及同样通过血红素琼脂糖亲和层析法分离得到的兔和大鼠Hx。在4℃下，使用人（通过两种方法获得的物种）或兔125I标记的血红素-Hx，通过Scatchard型分析测定每个细胞约3500 - 7000个高亲和力（Kd 0.34 - 0.85 nM）受体。同时测定，转铁蛋白受体数量和亲和力分别为40,000/细胞和0.83 nM。与转铁蛋白受体不同，细胞滋养层细胞培养24小时期间，Hx受体数量没有增加。在细胞滋养层细胞培养中，大鼠Hx与人Hx受体没有特异性结合。
