Hernandez A, Misle A, Urdaneta J, Dagger F
Department of Cell Biology, Faculty of Sciences, Universidad Central de Venezuela, Caracas.
Mol Biol Rep. 1987;12(2):103-10. doi: 10.1007/BF00368877.
Culture conditions of Leishmania cells were developed to allow the study of the effect of tunicamycin (TM) on glycosylation and on the cell surface components. Leishmania incorporate [14C]-mannose and [35S]-methionine in vitro. The incorporation of [14C]-mannose is linear for 150 min and is inhibited by TM (2 micrograms/ml) in a time dependent effect which reaches a plateau of 45% inhibition at 36 h. Under the same experimental conditions [35S]-methionine incorporation into protein is slightly affected. This is reflected by an almost identical polypeptide pattern for TM treated and non-treated cells when analyzed on SDS-PAGE. On the contrary, strong differences were detected on the labeled compounds analyzed on SDS-PAGE followed by autoradiography when the precursor used was [14C]-mannose. A shift in the electrophoretic mobility of most of the glycopeptides synthesized in the presence of TM was observed, which is also reflected in the structure of the main Leishmania cell surface components. The findings are discussed in the light of biological implications.
利什曼原虫细胞的培养条件得以建立，以便研究衣霉素（TM）对糖基化及细胞表面成分的影响。利什曼原虫可在体外掺入[14C] - 甘露糖和[35S] - 甲硫氨酸。[14C] - 甘露糖的掺入在150分钟内呈线性，且受TM（2微克/毫升）的时间依赖性抑制，在36小时时达到45%抑制的平台期。在相同实验条件下，[35S] - 甲硫氨酸掺入蛋白质的情况受轻微影响。当在SDS - PAGE上分析时，经TM处理和未处理的细胞呈现出几乎相同的多肽图谱，这反映了上述情况。相反，当使用[14C] - 甘露糖作为前体时，在SDS - PAGE上分析并经放射自显影检测的标记化合物存在显著差异。观察到在TM存在下合成的大多数糖肽的电泳迁移率发生了变化，这也反映在主要利什曼原虫细胞表面成分的结构中。根据生物学意义对这些发现进行了讨论。
