title: Utilization of leucine and acetate as carbon sources for sterol and fatty acid biosynthesis by Old and New World Leishmania species, Endotrypanum monterogeii and Trypanosoma cruzi.
abstract: The relative roles of acetate and leucine in the provision of a carbon source for fatty acid and sterol biosynthesis in several trypanosomatid species were investigated using 14C- and 13C-labelled acetate, glucose and leucine as substrates. Promastigotes of Leishmania species synthesized a large proportion of their sterol from leucine. L. major (LV39), L. amazonensis and L. mexicana were the most efficient utilizers of leucine, producing at least 70-77% of their sterol from leucine; L. braziliensis, L. donovani and L. tropica apparently produced less sterol from leucine (23-36%) and L. major (LV561), L. adleri and L. panamamensis were intermediate, utilizing leucine to provide 51-58% of their sterol. In all the cases the balance of the sterol produced was apparently synthesized from carbon arising from acetate. The related trypanosomatid Endotrypanum monterogeii also produced a large amount (77%) of its sterol from leucine rather than acetate. By contrast Trypanosoma cruzi elaborated only 8% of its sterol from leucine and used acetate far more effectively than the Leishmania species for sterol biosynthesis. The fatty acid moieties of the triacylglycerols and phospholipids were produced from acetate. Leucine was also incorporated into the fatty acids to varying extents in the different organisms showing that leucine can also be metabolized in trypanosomatids to generate acetyl-CoA.
authors.affiliation: School of Biological Sciences, Life Sciences Building, University of Liverpool, UK.
authors.forename: M L
authors.initials: ML
authors.lastname: Ginger
authors.forename: M C
authors.initials: MC
authors.lastname: Prescott
authors.forename: D G
authors.initials: DG
authors.lastname: Reynolds
authors.forename: M L
authors.initials: ML
authors.lastname: Chance
authors.forename: L J
authors.initials: LJ
authors.lastname: Goad
mesh_terms: D000085:Acetates / Q000378:metabolism*; D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology / Q000627:therapeutic use; D014355:Chagas Disease / Q000188:drug therapy; D002855:Chromatography, Thin Layer; D015195:Drug Design; D005227:Fatty Acids / Q000096:biosynthesis*; D008401:Gas Chromatography-Mass Spectrometry; D007896:Leishmaniasis / Q000188:drug therapy; D007930:Leucine / Q000378:metabolism*; D013045:Species Specificity; D013261:Sterols / Q000096:biosynthesis*; D014351:Trypanosomatina / Q000145:classification / Q000378:metabolism*
chemical_list: D000085:Acetates; D000981:Antiprotozoal Agents; D005227:Fatty Acids; D013261:Sterols; D007930:Leucine