Identification and initial characterisation of a Plasmodium falciparum Cox17 copper metallochaperone.

Copper is an essential micronutrient for all living organisms as an important catalytic co-factor for key enzymes. In higher eukaryotes intracellular copper is distributed by copper metallochaperones. Copper chelators such as neocuproine and tetrathiomolybdate inhibit Plasmodium falciparum erythrocytic development, indicating a requirement for copper by the parasite. A screen of the P. falciparum genome database identified eight potential copper-requiring protein orthologs, including four candidate copper metallochaperones implicated in the delivery of copper to cytochrome-c oxidase. A P. falciparum Cox17 ortholog (PfCox17) was recombinantly expressed and the purified protein bound reduced copper in vitro. PfCox17 was localised to the parasite cytoplasm. Characterisation of plasmodial proteins involved in copper metabolism will help us understand the role of this essential microelement in plasmodial homeostasis.