Moehring J M, Moehring T J
J Exp Med. 1968 Mar 1;127(3):541-54. doi: 10.1084/jem.127.3.541.
We have investigated the response of the resistant mouse L cell to diphtheria toxin. Intact cells and cell-free systems were studied. It was determined that the cell-free system is as sensitive to toxin as those from sensitive reticulocyte, HeLa, and KB cells previously studied. Poly-L-ornithine, reported to stimulate macromolecular uptake, enhanced toxin activity under conditions which also stimulated acid phosphatase activity. Resistance, in the L cell, appears to be linked to the cell membrane and the process of macromolecular uptake, and not to any intrinsic property of either the polyribosomes or associated protein synthesizing factors. Because of the unique way in which diphtheria toxin inhibits protein synthesis, the ability of poly-L-ornthine to enhance this action provides convincing evidence that poly-L-ornithine stimulates a true absorption of macromolecules and not just increased surface adsorption.
我们研究了抗性小鼠L细胞对白喉毒素的反应。对完整细胞和无细胞系统进行了研究。已确定无细胞系统与先前研究过的敏感网织红细胞、HeLa细胞和KB细胞的系统一样对毒素敏感。据报道，聚-L-鸟氨酸可刺激大分子摄取，在刺激酸性磷酸酶活性的条件下增强毒素活性。L细胞中的抗性似乎与细胞膜和大分子摄取过程有关，而与多核糖体或相关蛋白质合成因子的任何内在特性无关。由于白喉毒素抑制蛋白质合成的独特方式，聚-L-鸟氨酸增强这种作用的能力提供了令人信服的证据，表明聚-L-鸟氨酸刺激了大分子的真正吸收，而不仅仅是增加了表面吸附。
