van den Berg G J, van den Hamer C J
J Inorg Biochem. 1984 Oct;22(2):73-84. doi: 10.1016/0162-0134(84)80016-1.
Cultured rat hepatoma cells (HTC-cells) were used to study the transfer of copper from a well-defined medium to and across the cell membrane and particularly the role of albumin in this process. HTC-cells, maintained in a minimal salt-glucose medium, accumulated far more copper than when maintained in the same medium, but supplemented with albumin. In the latter case, the Cu uptake strongly depended on the molar Cu/albumin ratio. The results suggest a role of albumin in the uptake of trace metals. The results indicate the presence of two types of binding sites for copper on the cell membrane. The sites of the first type bind copper very strongly and are probably responsible for the uptake of copper under physiological conditions. Their number was estimated to be about 10(6) per cell. Those of the second type only bind copper when the molar Cu/albumin ratio exceeds a value of about 1, i.e., under extreme, unphysiological conditions. Furthermore, the results suggest a direct interaction of the Cu-albumin complex with these strong binding sites as a first step in Cu uptake processes.
培养的大鼠肝癌细胞（HTC 细胞）被用于研究铜从明确的培养基转移至细胞膜并穿过细胞膜的过程，特别是白蛋白在此过程中的作用。在最低盐 - 葡萄糖培养基中培养的 HTC 细胞积累的铜远比在相同培养基但添加了白蛋白时积累的铜多。在后一种情况下，铜的摄取强烈依赖于铜/白蛋白摩尔比。结果表明白蛋白在微量金属摄取中发挥作用。结果表明细胞膜上存在两种类型的铜结合位点。第一类位点与铜结合非常紧密，可能负责生理条件下铜的摄取。估计每个细胞这类位点的数量约为 10⁶ 个。第二类位点仅在铜/白蛋白摩尔比超过约 1 的值时，即在极端、非生理条件下才与铜结合。此外，结果表明铜 - 白蛋白复合物与这些强结合位点的直接相互作用是铜摄取过程的第一步。
