Primary Structure of a Lysine and Glutamate Rich Plasmodium Falciparum Antigen Located at the Merozoite Surface and in the Parasitophorous Vacuole.

摘要

We have previously characterized a 101 kDa Plasmodium Falciparum schizont antigen located at the merozoite surface and within the parasitoporous vacuolar space. We obtained Camp strain genomic DNA clones encoding 100% and FCR3 strain cDNA clones encoding 89% of the protein. A -galactosidase fusion protein expressed by one clone was recognized on immunoblots by monoclonal and affinity-purified polyclonal antibodies against the native antigen. Most antiserum against a synthetic peptide based on the deduced amino acid sequence of this clone detected a protein with electrophoretic mobility identical to the native schizont antigen on immunoblots. The gene encodes a protein of 743 amino acids which, except for a 22 amino acid hydrophobic leader sequence, is hydrophilic and highly charged. Near the N-terminus a 174 bp polypurine region encodes alternating KE and KEE sequences, and K and E constitute 14% of the total amino acid residues. (JS)