EPR spectroscopic studies of haemoglobin breakdown in malarial parasite-infected erythrocytes

Abstract

EPR spectra of an insoluble fraction from the rodent malarial parasite Plasmodium berghei, grown in mouse erythrocytes, have been measured. Signals due to high-spin iron(III) haem and two low-spin haem species were detected. Comparison with other derivatives of haemoglobin, and the use of a simple ligand-field model, identified the low-spin species as imidazole-hydroxy and bis-imidazole derivatives of haem. These species may represent intermediate stages in the breakdown of haemoglobin to the insoluble form, haemozoin. The utility of EPR spectroscopy for the study of the breakdown pathway is discussed.