Uptake of iron from N-terminal half-transferrin by isolated rat hepatocytes. Evidence of transferrin-receptor-independent iron uptake.
Uptake of iron from N-terminal half-transferrin by isolated rat hepatocytes. Evidence of transferrin-receptor-independent iron uptake.
复制标题
分离的大鼠肝细胞从 N 端半转铁蛋白中摄取铁。
DOI：
10.1111/j.1432-1033.1995.tb20790.x
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Aisen,P
中科院分区：
文献类型：
--
作者：
Thorstensen,K;Trinder,D;Zak,O;Aisen,P
The aim of the present study was to determine if human N‐terminal half‐transferrin (N‐fragment), prepared by thermolysin cleavage of diferric transferrin, would bind to the rat hepatocyte transferrin receptor and donate iron to the cell. Competition experiments between125I‐labelled N‐fragment and diferric transferrin revealed no receptor binding of the half‐transferrin. Still, the N‐fragment delivered iron to the cells in amounts approximately 30‐fold above what could be accounted for by uptake of the fragment itself. The rate of celluar iron uptake from the fragment was comparable to what is seen with the intact transferrin. The uptake of125I‐labelled N‐fragment was not inhibited by excess non‐radioactive diferric transferrin. By comparison, the uptake of59Fe from the N‐fragment was inhibited 70% by excess non‐radioactive diferric transferrin. This suggests that iron derived from diferric transferrin competes with the iron derived from the N‐fragment for a common transport pathway. Although some cellular degradation of the N‐fragment occurred, the extent of degradation was too low to explain the amount of iron accumulated by the cells. The results show that the hepatocyte has an effective transferrin‐receptor‐independent mechanism for accumulation of iron from transferrin.
