Binding of Plasmodium falciparum 175-kilodalton erythrocyte binding antigen and invasion of murine erythrocytes requires N-acetylneuraminic acid but not its O-acetylated form

Mol Biochem Parasitol. 1992 Mar;51(1):49-54. doi: 10.1016/0166-6851(92)90199-t.


Sialic acid on human erythrocytes is involved in invasion by the human malaria parasite, Plasmodium falciparum. Mouse erythrocytes were used as a reagent to explore the question of whether erythrocyte sialic acid functions as a nonspecific negative charge or whether the sialic acid is a necessary structural part of the receptor for merozoites. Human erythrocytes contain N-acetylneuraminic acid (Neu5Ac), whereas mouse erythrocytes, which are also invaded by P. falciparum merozoites, contain 9-O-acetyl-N-acetylneuraminic acid (Neu5,9Ac2) and N-glycoloylneuraminic acid (Neu5Gc), in addition to Neu5Ac. We compared the effects of sialidase and influenza C virus esterase treatments of mouse erythrocytes on invasion and the binding of a 175-kDa P. falciparum protein (EBA-175), a sialic acid-dependent malaria ligand implicated in the invasion process. Sialidase-treated mouse erythrocytes were refractory to invasion by P. falciparum merozoites and failed to bind EBA-175. Influenza C virus esterase, which converts Neu5,9Ac2 to Neu5Ac, increased both invasion efficiency and EBA-175 binding to mouse erythrocytes. Thus, the parasite and EBA-175 discriminate between Neu5Ac and Neu5,9Ac2, that is, the C-9 acetyl group interferes with EBA-175 binding and invasion by P. falciparum merozoites. This indicates that sialic acid is part of a receptor for invasion.

MeSH terms

  • Animals
  • Antigens, Protozoan / metabolism*
  • Binding Sites
  • Carrier Proteins / metabolism*
  • Erythrocytes / parasitology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred DBA
  • Plasmodium falciparum / metabolism*
  • Plasmodium falciparum / pathogenicity
  • Protozoan Proteins / metabolism*
  • Sialic Acids / metabolism*


  • Antigens, Protozoan
  • Carrier Proteins
  • Protozoan Proteins
  • Sialic Acids
  • erythrocyte-binding antigen 175, Plasmodium
  • 9-O-acetyl-N-acetylneuraminic acid