Glutamate rich Plasmodium falciparum antigen GLURP

RESUMO

We have characterized a glutamate rich Plasmodium falciparum antigen; GLURP; which by immunoassays appears to be present in both the preerythrocytic and erythrocytic stages of the vertebrate life cycle. The gene which is located on chromosome 10 encodes a polypeptide of 1271 residues with a predicted molecular mass of 145 kDa. Rabbit antiserum against a fusion protein expressing the C-terminal end of the molecule detects a protein with a molecular mass os 220 kDa. The sequence includes two hydrophobic regions; 23 residues near the N-terminus; which may act as a signal peptide; and a second located at the C-terminus consisting of 33 predominantly hydrophobic residues. Except for these hydrophobic regions the protein is hydrophilic and highly charged. The sequence has two tandem repeats designated R1 and R2 these regions are found to be conserved in isolates from different geographical areas. High levels of anti-GLURP antibodies have been shown to correlate with low parasite density. The indication of GLURP being expressed in all stages of the parasite in the human host raises significantly the prospects of the potential of this molecule