Incorporation of 14C-labelled non-lipid precursors into lipids of Plasmodium knowlesi in vitro

Abstract

1. 1. Plasmodium knowlesi incubated in vitro (either in intact host cells or free after hemolysis with saponin) incorporates 14C-labelled glucose, glycerol acetate, choline and ethanolamine into cell lipids, in contrast to host red cells which show no incorporation of these precursors into lipids. 2. 2. Eighty to ninety-five per cent of 14C incorporation by parasites is located in three major phospholipid classes: phosphatidylcholine, phosphatidylinositol and phosphatidylethanolamine. Most of the remaining 14C uptake occurs into two neutral lipid classes, di- and tri-glycerides. 3. 3. Eighty-five to ninety-five per cent of glucose and glycerol 14C activity appears in the glyceryl moiety of lipids, whereas acetate appears to be incorporated principally into the acyl portion, possibly through chain elongation rather than de novo biosynthesis of complete fatty acid molecules.