Association of diphtheria toxin with Vero cells. Demonstration of a receptor.
Association of diphtheria toxin with Vero cells. Demonstration of a receptor.
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白喉毒素与 Vero 细胞的关联。
DOI：
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发表时间：
1978
影响因子：
4.8
通讯作者：
S. Leppla
中科院分区：
文献类型：
--
作者：
J. Middlebrook;R. Dorland;S. Leppla
本文研究了放射性标记白喉毒素与高敏感性哺乳动物细胞系的相互作用。毒素在4和37摄氏度下以高度特异性的方式与Vero细胞结合（或被Vero细胞吸收）。在这两种温度下，过量的未标记的毒素竞争高达90%的细胞相关的标签。在37摄氏度的协会是双相的，增加到1至2小时的峰值，此后下降。在4摄氏度，随着时间的推移，协会增加到稳定状态。片段B和CRM-197都竞争标记毒素与细胞的结合。关联的大小与几种细胞系的细胞毒性敏感性相关。pH值和外源性核苷酸影响的协会在细胞毒性的影响一致的方式。在4摄氏度下与细胞相关的标记基本上是完整的毒素，而在37摄氏度下则被降解。在4摄氏度下，这种结合是可饱和的（K = 9 X 10（8）升/摩尔），是可逆的，并且表明约有1至2 X 10（5）个结合位点/细胞。
The interaction of radiolabeled diphtheria toxin with highly sensitive mammalian cell lines was studied. Toxin bound to (or was taken up by) Vero cells at 4 and 37 degrees C in a highly specific manner. At both temperatures, excess unlabeled toxin competed for up to 90% of the cell-associated label. The association at 37 degrees C was biphasic, increasing to a peak at 1 to 2 h and falling thereafter. At 4 degrees C, association increased with time to a steady state. Both fragment B and CRM-197 competed for the association of labeled toxin with cells. The magnitude of association correlated with the cytotoxic sensitivity of several cell lines. Both pH and exogenous nucleotides affected the association in a manner consistent with effects on cytotoxicity. The label associated with cells at 4 degrees C was largely intact toxin, while that at 37 degrees C was degraded. At 4 degrees C, the association was saturable (K = 9 X 10(8) liters/mol), was reversible, and indicated about 1 to 2 X 10(5) binding sites/cell.