Amsler K, Cook J S
J Cell Physiol. 1985 Feb;122(2):254-8. doi: 10.1002/jcp.1041220214.
With a clone of (Cl 4) of LLC-PK cells, which develop a high capacity for Na+-dependent hexose uptake over time (days) in culture, we show that increasing uptake capacity is paralleled by an increase in the number of phlorizin-binding sites in the population. The linear relationship between binding and hexose transport is the same whether the cells differentiate spontaneously or are induced by either methylisobutylxanthine or hexamethylene bisacetamide. The constancy of the relationship suggests that the primary factor in transport development is the number of transporters in the cells rather than other possible factors like a change in membrane potential or decreased efflux. The Kd for phlorizin binding is .08 +/- .04 microM, and corresponds to Ki of 0.10 microM for transport inhibition. The turnover number of the transporter is estimated to be 170 +/- 40 molecules per second of alpha-methyl glucoside.
利用LLC - PK细胞的克隆株（Cl 4），其在培养过程中（数天）对Na⁺依赖性己糖摄取的能力会随时间提高，我们发现摄取能力的增加与群体中根皮苷结合位点数量的增加平行。无论细胞是自发分化，还是由甲基异丁基黄嘌呤或六亚甲基双乙酰胺诱导分化，结合与己糖转运之间的线性关系都是相同的。这种关系的恒定性表明，转运发展的主要因素是细胞中转运体的数量，而非其他可能的因素，如膜电位变化或流出减少。根皮苷结合的Kd为0.08±0.04微摩尔，对应于转运抑制的Ki为0.10微摩尔。转运体的周转数估计为每秒170±40个α - 甲基葡萄糖苷分子。
