The aging of P. falciparum infected RBCs by 2D-correlation Raman and EPR spectroscopy

Abstract

Malaria is still a global health problem, especially when infection is caused by P. falciparum. In addition to its occurrence in endemic areas, it also takes the form of malaria imported by travelers. To understand the course of the disease, changes in the infected with P. falciparum red blood cells, in the process of their aging, were analyzed using Raman and EPR spectroscopy and the generalized 2D- COS method. The results were compared with the outcome of the natural aging process of human healthy blood cells. 2D correlation Raman synchronous peaks result from changes which reveals changes in erythrocytes caused by parasite invasion. First changes are connected with heme degradation- the aggregated heme and finally hemozoin. Other cross-peaks demonstrated the presence of hemoglobin breakdown products, which shows for example as the asparagine hemoglobinase impact. There are also observed complex changes in the erythrocyte membrane as the result of P. falciparum activity. The 2D asynchronous peaks are generated by phospholipids and the amino acids, His and Phe, that point to characteristic for P. falciparum protein family. The appearing 2D EPR correlation cross-peaks mainly come from iron ions, copper ions and peroxyl radicals. Iron ions in low- and high-spin complexes, related to the change of the geometry of paramagnetic centers, are the source of asynchronous cross-peaks indicating a complex process of iron transfer in the blood.