Merozoite surface protein 1 (MSP-1) (MSP-1)

Merozoite surface protein 1 (MSP-1) is a major surface glycoprotein of Plasmodium falciparum, the primary causative agent of malaria. It is synthesized as a 190-kDa precursor that undergoes complex proteolytic processing during schizont maturation and merozoite release. The C-terminal 42-kDa fragment (MSP-1_42) is further cleaved into a 33-kDa fragment and a 19-kDa fragment (MSP-1_19), the latter of which remains attached to the merozoite surface via a GPI anchor during erythrocyte invasion (UniProt P04932; PubMed: 11044379). The FVO variant refers to a specific allelic form (Falciparum Vietnam Oak-Knoll) that differs from other strains like 3D7, highlighting the significant antigenic polymorphism that complicates vaccine development (PubMed: 16439368). MSP-1 is a leading blood-stage vaccine candidate because antibodies against its C-terminal domains can inhibit parasite invasion of red blood cells. Clinical candidates like FMP1/AS02 have utilized the MSP-1_42 FVO fragment to elicit protective immune responses, though the high degree of sequence variation remains a therapeutic challenge (PubMed: 15713637).

Other names

MSP1MSP-1_42MSP-1_19p190Polymorphic schizont antigenMerozoite surface antigen 1MSP-1_42 (FVO)

Induction of neutralizing antibodies that inhibit the proteolytic processing of MSP-1 or physically block the interaction between the merozoite and the erythrocyte membrane, thereby preventing parasite entry into red blood cells.