Identification of the parasite transferrin receptor of Plasmodium falciparum-infected erythrocytes and its acylation via 1,2-diacyl-sn-glycerol.

The transferrin receptor of schizont-infected erythrocytes of Plasmodium falciparum (Gambian clone FCR-3/A2) is a parasite-encoded protein of Mr 102,000, which is present in purified erythrocyte membranes. Polyclonal antiserum to the purified Mr 102,000 protein was raised in rabbits. At physiological pH, immunoaffinity-purified protein bound human ferrotransferrin but not apotransferrin. Conversely, antibody to human transferrin was used to purify the ferrotransferrin-receptor complex from infected cells. The isolated receptor was specifically recognized by the polyclonal rabbit antiserum raised against the Mr 102,000 protein. Preliminary analysis indicated that, unlike the human receptor, the plasmodial transferrin receptor is not a disulfide linked dimer but a single polypeptide acylated via 1,2-diacyl-sn-glycerol.