PHOTOAFFINITY-LABELING OF PLASMODIUM-FALCIPARUM PROTEINS INVOLVED IN PHOSPHOLIPID TRANSPORT

Erythrocytes infected with mature-stage malaria parasites accumulate p hospholipids from exogenous sources. We show that the transport of -di palmitoyl-sn-glycero-3-phosphatidylethanolamine (N-NBD-DPPE), from the erythrocyte membrane to the intracellular malaria parasite, is depend ent upon metabolic energy. A photoreactive phospholipid analogue, 1,2- dilauryl-sn-glycero-3-phosphatidylethanolamine (N-I-125-ASA-DLPE), has been synthesised and used in an attempt to identify proteins involved in phospholipid trafficking in malaria-infected erythrocytes. This ph otoreactive probe was found to preferentially label a protein with an apparent molecular weight of 22 kDa. Photolabelling of the 22-kDa prot ein was enhanced upon ATP depletion of malaria-infected erythrocytes.