Resonance Raman spectroscopy can detect structural changes in haemozoin (malaria pigment) following incubation with chloroquine in infected erythrocytes

Webster, Grant T.; Tilley, Leann; Deed, Samantha; McNaughton, Don; Wood, Bayden R.

doi:10.1016/j.febslet.2008.02.062

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Volume 582, Issue 7 , Pages 1087-1092, 2 April 2008

Resonance Raman spectroscopy can detect structural changes in haemozoin (malaria pigment) following incubation with chloroquine in infected erythrocytes

Edited by Richard Cogdell

Grant T. Webster
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Vic. 3800, Australia
Leann Tilley
- Department of Biochemistry, La Trobe University, Melbourne, Vic. 3086, Australia
- Centre of Excellence for Coherent X-ray Science, La Trobe University, Melbourne, Vic. 3086, Australia
Samantha Deed
- Department of Biochemistry, La Trobe University, Melbourne, Vic. 3086, Australia
- Centre of Excellence for Coherent X-ray Science, La Trobe University, Melbourne, Vic. 3086, Australia
Don McNaughton
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Vic. 3800, Australia
Bayden R. Wood
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Vic. 3800, Australia
- Corresponding author. Fax: +61 3 9905 4597.

Received 15 January 2008; received in revised form 25 February 2008; accepted 25 February 2008. published online 04 March 2008.

Abstract

Resonance Raman spectroscopy was applied to monitor the effects of chloroquine (CQ) treatment on cultures of Plasmodium falciparum trophozoites. A number of bands assigned to A_1g and B_1g modes characteristic of the haemozoin aggregate are reduced in intensity in the CQ-treated cells, however, no bands from the CQ are observed. The intensity changes are attributed to intermolecular drug binding of the CQ in a sandwich type complex between ferriprotoporphyrin IX (FePPIX) dimer units. It is postulated that the CQ binds via π–π interactions between adjacent and orientated porphyrins thereby disrupting the haemozoin aggregate and reducing excitonic interactions between adjacent haems. The results show the potential of Raman microscopy as a screening tool for FePPIX:drug interactions in live cells.

Keywords: Malaria, Resonance Raman spectroscopy, Chloroquine, Chemometrics, Haemozoin