Malaria is caused by protozoan parasites of the genus Plasmodium. Four species of Plasmodium can infect humans: R falciparum, P. malariae, P. vivax, and P. ovale. P. falciparum is the only able to cytoadhere to the surface of postcapillary endothelial cells. A key role in cytoadherence is played by the interaction between the PfEMP1 P. falciparum protein and the human intracellular adhesion molecule (ICAM-1) although very little is known about the molecular details of this complex. Here we propose a model for this interaction on the basis of a homology model of the functional domain of PfEMP1 and of the ICAM-1 three dimensional structures. Our model is consistent with the results of many experimental observations, provides a rational explanation for the different binding abilities of different strains of R falciparum and explains the reduced binding affinity of the A4 strain of P. falciparum for the ICAM-1(Kilifi) polymorphism. On the basis of our model, we can also explain why the murine ICAM-1, although sharing 70% sequence similarity with its human homologue, does not bind PfEMP1, and why the binding of fibrinogen and PfFMP1 to ICAM-1 is mutually exclusive. The model of the complex proposed here can serve as a useful tool for the design and interpretation of biochemical and immunological experimental results.
A model of the complex between the PfEMP1 malaria protein and the human ICAM-1 receptor / Claudia, Bertonati; Tramontano, Anna. - In: PROTEINS. - ISSN 0887-3585. - STAMPA. - 69:2(2007), pp. 215-222. [10.1002/prot.21691]
A model of the complex between the PfEMP1 malaria protein and the human ICAM-1 receptor
TRAMONTANO, ANNA
2007
Abstract
Malaria is caused by protozoan parasites of the genus Plasmodium. Four species of Plasmodium can infect humans: R falciparum, P. malariae, P. vivax, and P. ovale. P. falciparum is the only able to cytoadhere to the surface of postcapillary endothelial cells. A key role in cytoadherence is played by the interaction between the PfEMP1 P. falciparum protein and the human intracellular adhesion molecule (ICAM-1) although very little is known about the molecular details of this complex. Here we propose a model for this interaction on the basis of a homology model of the functional domain of PfEMP1 and of the ICAM-1 three dimensional structures. Our model is consistent with the results of many experimental observations, provides a rational explanation for the different binding abilities of different strains of R falciparum and explains the reduced binding affinity of the A4 strain of P. falciparum for the ICAM-1(Kilifi) polymorphism. On the basis of our model, we can also explain why the murine ICAM-1, although sharing 70% sequence similarity with its human homologue, does not bind PfEMP1, and why the binding of fibrinogen and PfFMP1 to ICAM-1 is mutually exclusive. The model of the complex proposed here can serve as a useful tool for the design and interpretation of biochemical and immunological experimental results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.