Protein Farnesyltransferase from Trypanosoma brucei A HETERODIMER OF 61- AND 65-kDa SUBUNITS AS A NEW TARGET FOR ANTIPARASITE THERAPEUTICS

摘要: We have previously shown that protein prenylation occurs in the Trypanosomatids Trypanosoma brucei (T. brucei), cruzi, and Leishmania mexicana farnesyltransferase (PFT) activity can be detected cytosolic extracts of insect (procyclic) form T. brucei. A PFT transfers farnesyl group from pyrophosphate to a cysteine is 4 residues upstream C terminus Ras GTP-binding RAS1-CVIM has now been purified 60,000-fold near homogeneity procyclic By screening mixture hexapeptides SSCALX (X 20 different amino acids), it was found SSCALM binds with sub-micromolar affinity, affinity chromatography using this peptide key step purification enzyme. On SDS-polyacrylamide gel electrophoresis, enzyme migrates as pair bands apparent molecular masses 61 65 kDa, thus its subunits are approximately 30% larger than those mammalian homolog. The 61-kDa band identified putative beta-subunit by photoaffinity labeling 32P-labeled analog pyrophosphate. Mimetics C-terminal tetrapeptide prenyl acceptors inhibit PFT, these compounds also affinities nanomolar micromolar range, although structure-activity relationship very for parasite versus Unlike cells, growth bloodstream completely inhibited low concentrations two inhibitors, block farnesylation cultured parasites. These potently intracellular (amastigote) cruzi grown fibroblast host cells. results suggest target development anti-trypanosomatid chemotherapeutics.