The 10 kDa domain of human erythrocyte protein 4.1 binds the Plasmodium falciparum EBA-181 protein

4.1R structural domains (30, 16, 10 and 22 kDa domain) and the 4.1R binding region in EBA-181 were synthesized in specific Escherichia coli strains as recombinant proteins and purified using magnetic bead technology. Recombinant proteins were subsequently used in blot-overlay and histidine pull-down assays to determine the binding domain in 4.1R.Blot overlay and histidine pull-down experiments revealed specific interaction between the 10 kDa domain of 4.1R and EBA-181. Binding was concentration dependent as well as saturable and was abolished by heat denaturation of 4.1R.The interaction of EBA-181 with the highly conserved 10 kDa domain of 4.1R provides new insight into the molecular mechanisms utilized by P. falciparum during erythrocyte entry. The results highlight the potential multifunctional role of malaria invasion proteins, which may contribute to the success of the pathogenic stage of the parasite's life cycle.Malaria is caused by a group of infectious protozoan parasites that alters the physiological functioning and cellular biology of erythrocytes. Plasmodium falciparum is the best-studied species and is the commonest, most virulent and principal cause of the majority of infections and deaths worldwide. Since the completion of the parasite's genome sequence [1], a wealth of knowledge has been generated through proteomic and genomic studies. High-throughput screening [2,3], protein identification technology such as mass spectrometry [4-7] and gene knockdown/knockout technology [8-13] are some of the methods that have been used to decipher complex molecular processes governing the life cycle of P. falciparum.The invasion of erythrocytes by P. falciparum initiates the pathogenic phase of the life cycle and is essential for parasite survival and progression of clinical malaria [14]. Invasion is a complex process involving a series of molecular interactions between P. falciparum merozoites and erythrocyte membrane receptors. Mediators of invasion have been iden