The Merozoite Surface Protein 1 of Plasmodium Falcipurum: Interaction with the Surface of Human Erythrocytes and with Surface Proteins Msp-6 and Msp-7

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.