Planas-Bohne F, Rau W
Kernforschungszentrum Karlsruhe, Institut für Genetik und für Toxikologie von Spaltstoffen, Karlsruhe, FRG.
Hum Exp Toxicol. 1990 Jan;9(1):17-24. doi: 10.1177/096032719000900105.
The binding of the 59Fe and 239Pu complexes of transferrin and 125I labelled transferrin [Tf (125I)] to isolated cell membranes of rat liver has been studied. Transferrin forms a complex with an integral protein of the membrane which has an apparent molecular weight of about 180 kDa and is stable only at pH 7.4. Iron-59 is eluted from Sephacryl S 300 columns together with Tf (125I) or the Tf-membrane protein complex while 239Pu seems to be bound to different membrane protein(s). After isolation of the Tf-binding protein from 35S-labelled membranes and incubation with one of the metal-Tf complexes 59Fe elutes from a Sephacryl S 300 column together with 35S at an apparent molecular weight of ca. 250 kDa while 239Pu is found in fractions of lower molecular weight. It is concluded from these results that there are Tf-receptors in the liver cell membrane to which iron transferrin may bind. Plutonium, however, seems to be dissociated from Tf and bound directly to other membrane proteins.
已对转铁蛋白的59Fe和239Pu复合物以及125I标记的转铁蛋白[Tf(125I)]与大鼠肝脏分离细胞膜的结合进行了研究。转铁蛋白与一种膜整合蛋白形成复合物，该蛋白的表观分子量约为180 kDa，且仅在pH 7.4时稳定。59Fe与Tf(125I)或Tf-膜蛋白复合物一起从Sephacryl S 300柱上洗脱，而239Pu似乎与不同的膜蛋白结合。从35S标记的膜中分离出Tf结合蛋白并与其中一种金属-Tf复合物孵育后，59Fe与35S一起从Sephacryl S 300柱上以约250 kDa的表观分子量洗脱，而239Pu存在于较低分子量的组分中。从这些结果可以得出结论，肝细胞膜中存在转铁蛋白受体，铁转铁蛋白可能与之结合。然而，钚似乎从转铁蛋白上解离并直接与其他膜蛋白结合。
