Synthesis, solution structure and immune recognition of an epidermal growth factor-like domain from Plasmodium falciparum merozoite surface protein-1.
The Plasmodium falciparum merozoite surface protein-1 19 kDa fragment (MSP-1(19)) comprises two closely packed EGF-like domains (EGF=epidermal growth factor), each stabilized by three disulfide bonds. The native conformation of this protein is important for eliciting P. falciparum growth inhibitory antibodies. Here we show that the N-terminal EGF domain alone can be chemically synthesized and efficiently refolded to a native-like state, as shown by its solution structure as determined by NMR spectroscopy. In order to study its immunogenicity, the domain was coupled through its N terminus to a phospholipid and incorporated into reconstituted influenza virus-like particles (virosomes). When used to immunize mice, the peptide-loaded virosomes elicited potent humoral immune responses that were shown by Western blots and immunofluorescence assays to cross-react with native MSP-1 on the surfaces of P. falciparum blood stage parasites. This opens the way for a medicinal chemistry-oriented approach to the study and optimization of the antigenicity of the protein as a potential malaria vaccine candidate, whilst exploiting the immunopotentiating properties of influenza virosomes as a delivery vehicle.
James
Sonya
S
Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
Moehle
Kerstin
K
Renard
Annabelle
A
Mueller
Markus S
MS
Vogel
Denise
D
Zurbriggen
Rinaldo
R
Pluschke
Gerd
G
Robinson
John A
JA
D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000917:Antibody Formation; D000918:Antibody Specificity; D004815:Epidermal Growth Factor / Q000276:immunology*; D007159:Immunologic Tests; D009682:Magnetic Resonance Spectroscopy; D020066:Merozoite Surface Protein 1 / Q000737:chemistry* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry* / Q000276:immunology*; D010963:Plasmodium falciparum / Q000737:chemistry* / Q000276:immunology; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry* / Q000276:immunology; D015800:Protozoan Proteins / Q000737:chemistry* / Q000276:immunology; D012996:Solutions / Q000737:chemistry; D022701:Virosomes / Q000008:administration & dosage / Q000737:chemistry / Q000276:immunology
D000913:Antibodies, Protozoan; D020066:Merozoite Surface Protein 1; D010446:Peptide Fragments; D021122:Protein Subunits; D015800:Protozoan Proteins; D012996:Solutions; D022701:Virosomes; D004815:Epidermal Growth Factor