Alonso M A, Carrasco L
Eur J Biochem. 1982 Oct;127(3):567-9. doi: 10.1111/j.1432-1033.1982.tb06909.x.
Mammalian cells become permeable to low-molecular-weight compounds and proteins when they are treated with nigericin. Concentrations of this ionophore that have no effect on protein synthesis induce the entry of the translation inhibitors hygromycin B (Mr 550) and kappa-sarcin (Mr 16800). Treatment of HeLa cells with low concentrations of nigericin stimulate the (Na+/K+)ATPase and, as a consequence, increase the plasma membrane potential. A correlation is observed between the increase in membrane potential and the entry of antibiotics and protein toxins into cells. These results suggest a relationship between the two phenomena and help an understanding of the molecular mechanism for the passage of charged molecules and proteins into mammalian cells. This permeabilization is specific for certain ionophores, such as nigericin and monensin, and does not occur on treatment with amphotericin B, valinomycin or A23187. These compounds depolarize the plasma membrane and drastically block protein synthesis in HeLa cells under these conditions.
当用尼日利亚菌素处理时，哺乳动物细胞会对低分子量化合物和蛋白质变得具有通透性。这种对蛋白质合成无影响的离子载体浓度会诱导翻译抑制剂潮霉素B（分子量550）和κ-肌动蛋白（分子量16800）进入细胞。用低浓度的尼日利亚菌素处理HeLa细胞会刺激（Na+/K+）ATP酶，结果增加了质膜电位。观察到膜电位的增加与抗生素和蛋白质毒素进入细胞之间存在相关性。这些结果表明这两种现象之间存在关联，并有助于理解带电分子和蛋白质进入哺乳动物细胞的分子机制。这种通透性对某些离子载体具有特异性，如尼日利亚菌素和莫能菌素，而在用两性霉素B、缬氨霉素或A23187处理时不会发生。在这些条件下，这些化合物会使质膜去极化并严重阻断HeLa细胞中的蛋白质合成。
