The Merozoite Surface Protein 1 of Plasmodium falcipurum

Binding of merozoite proteins to erythrocyte during invasion is a critical step. However, little is known about interactions occurring during merozoite invasion of erythrocytes or complex formation of merozoite surface proteins among themselves.One such important merozoite proteins thought to play a crucial role during invasion of RBCs is Merozoite surface protein 1 (MSP-1), a potential candidate for blood stage vaccine development. In this work, an in vitro interaction assay of MSP-1 with human erythrocytes is described to investigate which subunit of MSP-1 bind to Erythrocytes. Although the specificity of the binding is not clear, our data indicates p38 and p42 appears to interact with erythrocytes. Taken together our data suggest that MSP-1 by itself might not be an initial interaction partner for erythrocytes. Interestingly, our data from association study between MSP-1 and MSP-6 performed in this work clearly indicate that hMSP-6 interacts with MSP-1 complexes as long as p38 is present making this subunit the most important interaction partner. Moreover, we also fine map a stretch of 51 amino acids in MSP-6 responsible for the interaction with MSP-1.