Hoffmann M E, Jang J, Moreno S N, Docampo R
Department of Veterinary Pathobiology, University of Illinois at Urbana-Champaign 61801, USA.
J Eukaryot Microbiol. 1995 May-Jun;42(3):293-7. doi: 10.1111/j.1550-7408.1995.tb01583.x.
[35S]methionine incorporation into proteins of either T. cruzi epimastigotes or trypomastigotes was drastically inhibited by low concentrations of crystal violet in a dose-dependent manner. This inhibition was not due to ATP depletion since cellular ATP levels did not change significantly after incubation of epimastigotes with 50 microM crystal violet for similar periods of time, and was unaffected by changes in the extracellular free calcium concentration. Although crystal violet was able to inhibit protein synthesis in a cell-free system from T. cruzi epimastigotes, half maximal inhibition was at 1 mM, a concentration three orders of magnitude higher than those that inhibited protein synthesis in intact cells. On the other hand, crystal violet was able to inhibit total [35S]methionine uptake at similar concentrations to those that inhibited protein synthesis while addition of increasing concentrations of cold methionine to the incubation medium protected the cells against crystal violet inhibition. Crystal violet also inhibited total [3H]proline uptake thus indicating that it has a general inhibitory effect upon the transport of amino acids, and not specifically upon methionine. These results indicate that inhibition of protein synthesis by crystal violet is probably due to inhibition of amino acid uptake.
低浓度结晶紫能以剂量依赖的方式显著抑制[35S]甲硫氨酸掺入克氏锥虫前鞭毛体或 trypomastigotes 的蛋白质中。这种抑制作用并非由于 ATP 耗竭，因为在用 50 microM 结晶紫孵育前鞭毛体相同时间段后，细胞内 ATP 水平并未显著变化，且不受细胞外游离钙浓度变化的影响。虽然结晶紫能够抑制来自克氏锥虫前鞭毛体的无细胞体系中的蛋白质合成，但半数最大抑制浓度为 1 mM，此浓度比抑制完整细胞中蛋白质合成的浓度高三个数量级。另一方面，结晶紫能够在与抑制蛋白质合成相似的浓度下抑制总的[35S]甲硫氨酸摄取，而向孵育培养基中添加浓度递增的冷甲硫氨酸可保护细胞免受结晶紫的抑制。结晶紫还抑制总的[3H]脯氨酸摄取，因此表明它对氨基酸转运具有普遍抑制作用，而非特异性地针对甲硫氨酸。这些结果表明，结晶紫对蛋白质合成的抑制可能是由于对氨基酸摄取的抑制。
