Hermoso T, Jaffe C L
Instituto de Medicina Tropical, Universidad Central de Venezuela, Caracas.
Biol Res. 1993;26(1-2):267-71.
Protein kinases are present in the plasma membrane of the human parasite Leishmania. A marked increase in enzyme activity has been detected as cultures entered into the stationary phase of growth. Since avirulent parasites can be separated from virulent forms by the peanut agglutinin (PNA), we have examined the change in the protein kinase activity of L. major during growth in vitro and the difference in phosphorylation with virulent promastigotes (PNA-) of L. major. Marked similarities were found between the phosphorylation patterns of the logarithmic and stationary phase promastigotes of L. major. On the other hand, when the phosphorylation pattern of those proteins, shared by both the metacyclic (PNA-) promastigotes and the stationary phase cells, was examined, a marked increase in both the total number of phosphoproteins and the extent of their phosphorylation was observed in PNA-. Both the increase in protein kinase activity in the stationary phase parasites and the marked changes in phosphorylation in the highly infective promastigotes, may provide a clue as to the adaptative mechanism which enable promastigotes to survive within the vertebrate host.
蛋白激酶存在于人类寄生虫利什曼原虫的质膜中。随着培养物进入生长稳定期，已检测到酶活性显著增加。由于无毒力的寄生虫可通过花生凝集素（PNA）与有毒力的形式分离，我们研究了杜氏利什曼原虫在体外生长过程中蛋白激酶活性的变化以及杜氏利什曼原虫有毒力前鞭毛体（PNA-）磷酸化的差异。在杜氏利什曼原虫对数期和稳定期前鞭毛体的磷酸化模式之间发现了显著的相似性。另一方面，当检查循环后期（PNA-）前鞭毛体和稳定期细胞共有的那些蛋白质的磷酸化模式时，在PNA-中观察到磷酸化蛋白的总数及其磷酸化程度均显著增加。稳定期寄生虫中蛋白激酶活性的增加以及高感染性前鞭毛体中磷酸化的显著变化，可能为前鞭毛体在脊椎动物宿主体内存活的适应性机制提供线索。
