Expressing full-length functional PfEMP1 proteins in the HEK293 expression system.

Due to the A/T-richness of the genome of Plasmodium falciparum, expressing P. falciparum proteins in heterologous expression systems is challenging. In addition, many P. falciparum proteins have high cysteine content and high molecular weight, which further complicates expression of these proteins in heterologous systems. The high molecular weight Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) adhesins expressed on the surface of the infected erythrocytes are among the most difficult proteins to express. Cost reduction in synthetic gene synthesis, as well as improved eukaryotic expression systems, now makes it possible to express such proteins. In this chapter, we describe the construction, production, purification, and functional assessment of the full-length extracellular region of the var2CSA PfEMP1 protein involved in pregnancy-associated malaria (PAM), using a human embryonic kidney (HEK) expression system.