GLYCOSYLPHOSPHATIDYLINOSITOLS OF PLASMODIUM-CHABAUDI CHABAUDI - A BASIS FOR THE STUDY OF MALARIAL GLYCOLIPID TOXINS IN A RODENT MODEL

Free and protein-bound glycosylphosphatidylinositols (GPIs) of the blo od stages of the rodent malarial parasite Plasmodium chabaudi chabaudi AS were identified and characterized. TLC analysis of material extrac ted by organic solvents from metabolically labelled parasites revealed a distinct set of glycolipids. These glycolipids were identified as G PIs by specific chemical and enzymic treatments and by structural anal ysis of their glycan and hydrophobic parts. These analyses revealed th at P. c. chabaudi AS synthesizes a set of GPI-biosynthesis intermediat es and two potential GPI-anchor precursors exhibiting the following st ructures: ethanolamine-phosphate [(alpha 1-2)mannose]mannose(alpha 1-2 )mannose(alpha 1-6) mannose(alpha 1-4)glucosamine-(acyl) inositol-phos phate-diacylglycerol (P. ch. alpha) and ethanolaminephosphate-mannose( alpha 1-2)mannose(alpha 1-6) mannose(alpha 1-4)glucosamine-(acyl)inosi tol-phosphate- diacylglycerol (P. ch. beta). One of these GPI-anchor p recursors (P. ch. alpha) possesses the same carbohydrate structure as the GPI membrane anchor of merozoite surface protein-1 from P. c. chab audi AS.