Volume 13 Supplement 1

Challenges in malaria research: Core science and innovation

Open Access

Preliminary studies of biosynthesis of heme O and heme A in intraerythrocytic stages of P. falciparum

  • Raquel Simão-Gurge1,
  • Julia Cricco2,
  • Gerhard Wunderlich1,
  • Emilia Kimura1,
  • Brenda Cirulli2 and
  • Alejandro Katzin1
Malaria Journal201413(Suppl 1):P82


Published: 22 September 2014


Intermediates of the isoprenoid metabolism can bind to heme groups. Heme is critical and its derivatives, heme O and heme A, are the main compounds of aerobic respiration. They are synthesized by farnesylation of heme groups by “heme O synthase” (HOS or Cox10) and “heme A synthase” (HAS or Cox15). The identification of heme O and heme A and characterization of enzymes involved in their synthesis are important for exploring the possible products biosynthesized by the parasite derived from the MEP pathway. Importantly, hemes A and O are essential molecules for numerous living organisms, since they are critical components of the mitochondrial electron transport chain, catalyzing the reduction of O2 to H2O. Additionally, the heme group is an important target of drugs such as artemisinin and quinolines.


The characterization of heme O in P. falciparum was done by two different methods using metabolic labeling with [3H] FPP and [14C] Glycine followed by extraction and separation through a C18 column permitting to observe heme O as well as heme B biosynthesis. The plasmodial orthologs of HOS (PfCox10) and HAS (PfCox15) genes were identified by their homology to HOS and HAS enzymes from other organisms. We then genetically tagged both genes with GFP and HA coding sequences and visualized transfectants by fl uorescence microscopy.

Results and conclusion

We observed production of heme O and heme B in blood stage parasites. Visualization tagged PfCox10 and PfCox15 suggested that both enzymes were most probably localized in the mitochondria although PfCox10 presented an unusual extension at its N-terminus.

Authors’ Affiliations

University of São Paulo
The National University of Rosario


© Simão-Gurge et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.