States B, Foreman J, Lee J, Harris D, Segal S
Metabolism. 1987 Apr;36(4):356-62. doi: 10.1016/0026-0495(87)90207-1.
The transport of the amino acids, cystine and lysine, was studied in epithelial cell lines propagated from human kidney cortex. Cystine uptake data were reproducible in different cell lines and did not vary over several cell passages of an individual cell line. The transport of this disulfide amino acid was sodium-dependent with kinetic analysis showing one apparent Kt system of 0.09 mmol/L and Vmax of 0.054 mmol/L cell water/min. Studies of the kinetics of lysine transport, however, revealed two uptake systems with apparent high and low affinities with Kt of 0.14 mmol/L and 5 mmol/L and Vmax of 0.041 and 0.167 mmol/L cell water/min, respectively. Glutamate appeared to be the most potent inhibitor of cystine uptake by these cultured human renal cells and this interaction was competitive. Although cystine did not inhibit lysine uptake, arginine and ornithine were shown to be major inhibitors, thus providing evidence for the presence of a shared dibasic amino acid transport system.
对从人肾皮质传代培养的上皮细胞系中氨基酸、胱氨酸和赖氨酸的转运进行了研究。胱氨酸摄取数据在不同细胞系中具有可重复性，并且在单个细胞系的几次传代过程中没有变化。这种二硫氨基酸的转运依赖于钠，动力学分析显示一个表观Kt系统，其值为0.09 mmol/L，Vmax为0.054 mmol/L细胞水/分钟。然而，赖氨酸转运动力学研究揭示了两个摄取系统，分别具有表观高亲和力和低亲和力，其Kt分别为0.14 mmol/L和5 mmol/L，Vmax分别为0.041和0.167 mmol/L细胞水/分钟。谷氨酸似乎是这些培养的人肾细胞摄取胱氨酸的最有效抑制剂，并且这种相互作用是竞争性的。虽然胱氨酸不抑制赖氨酸摄取，但精氨酸和鸟氨酸被证明是主要抑制剂，从而为存在共享的二价氨基酸转运系统提供了证据。
