Mas A, Sarkar B
Research institute, Hospital for Sick Children, Toronto, Canada.
Biochim Biophys Acta. 1992 Jun 10;1135(2):123-8. doi: 10.1016/0167-4889(92)90127-w.
The isolated human trophoblast was used as a system to analyze the effects of different physiological ligands on cellular uptake of copper. The results show that the uptake of copper by these cells follows a similar pattern for the ligands tested (histidine, albumin and ceruloplasmin) as that for copper chloride. The process follows a typical hyperbolic curve at 37 degrees C. The initial phase of uptake follows a linear pattern during 30 min at 37 degrees C and at least 60 min at 4 degrees C from which the uptake rate is calculated. However, a significant decrease in the uptake rate is observed for albumin. The effect of histidine on stimulating copper transport is observed in the presence of serum, a phenomenon which is considered to be due to the release of copper that is bound to albumin. These results support the role of ceruloplasmin as a copper transport protein which releases copper at the cell surface, and a subsequent transport of the released copper in a manner similar to that of copper chloride or copper-histidine complexes.
分离出的人滋养层细胞被用作一个系统，以分析不同生理配体对铜细胞摄取的影响。结果表明，这些细胞对铜的摄取模式与测试的配体（组氨酸、白蛋白和铜蓝蛋白）以及氯化铜相似。该过程在37℃时呈现典型的双曲线。摄取的初始阶段在37℃下30分钟内以及在4℃下至少60分钟内呈线性模式，据此计算摄取速率。然而，观察到白蛋白的摄取速率显著下降。在血清存在的情况下观察到组氨酸对刺激铜转运的作用，这种现象被认为是由于与白蛋白结合的铜的释放。这些结果支持铜蓝蛋白作为一种铜转运蛋白的作用，它在细胞表面释放铜，随后以类似于氯化铜或铜 - 组氨酸复合物的方式转运释放的铜。
