formycins and Leishmaniasis--Cutaneous

Promastigotes of L. aethiopica express an ectokinase activity preferring histone V-S as substrate. A soluble kinase activity utilizing protamine and histone V-S, as well as a particulate fraction associated kinase activity preferring protamine are also expressed. The soluble histone kinase activity, but not the ectokinase, was expressed at a higher level in cells from late phases of growth, as compared to early log phase cultures. Transformation of L. aethiopica to an amastigote-like stage, resulted in almost complete loss of the kinase activities, with retained viability of the cells. Formycin-ATP only weakly inhibited the kinases while effectively inhibiting cell growth and thymidine incorporation. Staurosporin efficiently blocked the kinase activities and cell growth without affecting thymidine incorporation.

Topics: Alkaloids; Animals; Formycins; Histones; Humans; Leishmania; Leishmaniasis, Cutaneous; Protamines; Protein Kinase Inhibitors; Protein Kinases; Ribonucleotides; Solubility; Staurosporine; Subcellular Fractions; Substrate Specificity