The baculovirus-expressed binding region of Plasmodium falciparum EBA-140 ligand and its glycophorin C binding specificity

PLoS One. 2015 Jan 14;10(1):e0115437. doi: 10.1371/journal.pone.0115437. eCollection 2015.

Abstract

The erythrocyte binding ligand 140 (EBA-140) is a member of the Plasmodium falciparum DBL family of erythrocyte binding proteins, which are considered as prospective candidates for malaria vaccine development. The EBA-140 ligand is a paralogue of the well-characterized P. falciparum EBA-175 protein. They share homology of domain structure, including Region II, which consists of two homologous F1 and F2 domains and is responsible for ligand-erythrocyte receptor interaction during invasion. In this report we describe, for the first time, the glycophorin C specificity of the recombinant, baculovirus-expressed binding region (Region II) of P. falciparum EBA-140 ligand. It was found that the recombinant EBA-140 Region II binds to the endogenous and recombinant glycophorin C, but does not bind to Gerbich-type glycophorin C, neither normal nor recombinant, which lacks amino acid residues 36-63 of its polypeptide chain. Our results emphasize the crucial role of this glycophorin C region in EBA-140 ligand binding. Moreover, the EBA-140 Region II did not bind either to glycophorin D, the truncated form of glycophorin C lacking the N-glycan or to desialylated GPC. These results draw attention to the role of glycophorin C glycans in EBA-140 binding. The full identification of the EBA-140 binding site on glycophorin C molecule, consisting most likely of its glycans and peptide backbone, may help to design therapeutics or vaccines that target the erythrocyte binding merozoite ligands.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Baculoviridae / immunology*
  • Carrier Proteins / metabolism*
  • Erythrocytes / metabolism*
  • Glycophorins / metabolism*
  • Malaria Vaccines / immunology
  • Malaria, Falciparum / immunology
  • Malaria, Falciparum / prevention & control
  • Membrane Proteins
  • Plasmodium falciparum
  • Protein Binding
  • Protozoan Proteins / metabolism*

Substances

  • Carrier Proteins
  • EBA140 protein, Plasmodium falciparum
  • Glycophorins
  • Malaria Vaccines
  • Membrane Proteins
  • Protozoan Proteins

Grants and funding

The research was supported by grants No N N302 281436 from the Ministry of Science and Higher Education of Poland and grant No 2012/05/N/NZ6/00667 from National Centre of Science.