Leishmania donovani possess a NADPH-dependent alkylglycerol cleavage enzyme

Leishmania parasites possess an abundance of ether-linked hydrocarbons as components of phospholipids and glycosylphosphatidylinositol anchors of glycoproteins and polysaccharides, including important surface molecules such as lipophosphoglycan (LPG) and glycosylinositolphospholipids (GIPLs). Cleavage of the ether bond is an important feature in the turnover pathway of alkylglycerols. In mammals, ether lipid cleavage activity requires a pteridine cofactor (H4 biopterin), suggesting the potential for linkage between the unusual Leishmania pteridine metabolic pathways and lipid metabolism. In this study, we partially purified and characterized an activity in L. donovani capable of cleaving the ether lipid 1-O-alkyl[3H]glycol. Unlike the mammalian enzyme but like that of Tetrahymena, the Leishmania enzyme required NADPH rather than H4-biopterin. The use of divergent cofactors by the parasite and mammalian enzymes may provide a basis for the design of anti-parasitic drugs targeting ether-linked lipid metabolism.