Synthesis, Solution Structure and Immune Recognition of an Epidermal Growth Factor‐Like Domain from Plasmodium falciparum Merozoite Surface Protein‐1

Abstract

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.

Chromatin state dynamics during the Plasmodium falciparum intraerythrocytic development cycle

“…Merozoite surface protein 1 (MSP1) (PF3D7_0930300) is one of the most highly abundant proteins on the merozoite surface [ 74 – 76 ]. MSP1-encoding mRNA transcripts increase beginning in the schizont stage while the parasite is still developing inside the host cell.…”

Chromatin state dynamics during the Plasmodium falciparum intraerythrocytic development cycle

“…Merozoite surface protein 1 (MSP1) (PF3D7_0930300) is one of the most highly abundant proteins on the merozoite surface [ 74 – 76 ]. MSP1-encoding mRNA transcripts increase beginning in the schizont stage while the parasite is still developing inside the host cell.…”

Chromatin state dynamics during the Plasmodium falciparum intraerythrocytic development cycle

“…Merozoite surface protein 1 (MSP1) (PF3D7_0930300) is one of the most highly abundant proteins on the merozoite surface and as such is a promising vaccine candidate (Child et al, 2010; Das et al, 2015; James et al, 2006). MSP1 expression begins in the schizont stage while the parasite is still developing inside the host cell.…”

Antigenicity of a Bacterially Expressed Triple Chimeric Antigen of Plasmodium falciparum AARP, MSP-311 and MSP-119: PfAMSP-Fu35

“…coli is expressed as a soluble protein and that the 19kDa fragment is always appropriately folded through six disulphide bonds [26,27]. This may point out an inherent conformational preference that this EGF like domain has and may well suggest as some crucial functional role for this region of PfMSP-1 [39]. …”

Chromatin state dynamics during the Plasmodium falciparum intraerythrocytic development cycle

“…Merozoite surface protein 1 (MSP1) (PF3D7_0930300) is one of the most highly abundant proteins on the merozoite surface [ 74 – 76 ]. MSP1-encoding mRNA transcripts increase beginning in the schizont stage while the parasite is still developing inside the host cell.…”

Chromatin state dynamics during the Plasmodium falciparum intraerythrocytic development cycle

“…Merozoite surface protein 1 (MSP1) (PF3D7_0930300) is one of the most highly abundant proteins on the merozoite surface and as such is a promising vaccine candidate (Child et al, 2010; Das et al, 2015; James et al, 2006). MSP1 expression begins in the schizont stage while the parasite is still developing inside the host cell.…”

Antigenicity of a Bacterially Expressed Triple Chimeric Antigen of Plasmodium falciparum AARP, MSP-311 and MSP-119: PfAMSP-Fu35

“…coli is expressed as a soluble protein and that the 19kDa fragment is always appropriately folded through six disulphide bonds [26,27]. This may point out an inherent conformational preference that this EGF like domain has and may well suggest as some crucial functional role for this region of PfMSP-1 [39]. …”

Chromatin state dynamics during the Plasmodium falciparum intraerythrocytic development cycle

“…Merozoite surface protein 1 (MSP1) (PF3D7_0930300) is one of the most highly abundant proteins on the merozoite surface [ 74 – 76 ]. MSP1-encoding mRNA transcripts increase beginning in the schizont stage while the parasite is still developing inside the host cell.…”

Chromatin state dynamics during the Plasmodium falciparum intraerythrocytic development cycle

“…Merozoite surface protein 1 (MSP1) (PF3D7_0930300) is one of the most highly abundant proteins on the merozoite surface and as such is a promising vaccine candidate (Child et al, 2010; Das et al, 2015; James et al, 2006). MSP1 expression begins in the schizont stage while the parasite is still developing inside the host cell.…”

Antigenicity of a Bacterially Expressed Triple Chimeric Antigen of Plasmodium falciparum AARP, MSP-311 and MSP-119: PfAMSP-Fu35

“…coli is expressed as a soluble protein and that the 19kDa fragment is always appropriately folded through six disulphide bonds [26,27]. This may point out an inherent conformational preference that this EGF like domain has and may well suggest as some crucial functional role for this region of PfMSP-1 [39]. …”