Jigang Wang a , 1 , 2 , 3 , 4 , Chong-Jing Zhang 5 , Wan Ni Chia 6 , Cheryl C. Y. Loh 6 , Zhengjun Li 7 , Yew Mun Lee 1 , Yingke He 8 , Li-Xia Yuan 9 , Teck Kwang Lim 1 , Min Liu 3 , Chin Xia Liew 7 , Yan Quan Lee 6 , Jianbin Zhang 4 , Nianci Lu 10 , Chwee Teck Lim 11 , 12 , Zi-Chun Hua 2 , Bin Liu 5 , Han-Ming Shen 4 , Kevin S. W. Tan b , 6 , Qingsong Lin c , 1 , 7
22 December 2015
The mechanism of action of artemisinin and its derivatives, the most potent of the anti-malarial drugs, is not completely understood. Here we present an unbiased chemical proteomics analysis to directly explore this mechanism in Plasmodium falciparum. We use an alkyne-tagged artemisinin analogue coupled with biotin to identify 124 artemisinin covalent binding protein targets, many of which are involved in the essential biological processes of the parasite. Such a broad targeting spectrum disrupts the biochemical landscape of the parasite and causes its death. Furthermore, using alkyne-tagged artemisinin coupled with a fluorescent dye to monitor protein binding, we show that haem, rather than free ferrous iron, is predominantly responsible for artemisinin activation. The haem derives primarily from the parasite's haem biosynthesis pathway at the early ring stage and from haemoglobin digestion at the latter stages. Our results support a unifying model to explain the action and specificity of artemisinin in parasite killing.
The mechanism of action of artemisinin, an antimalarial drug, is not well understood. Here, the authors use a labelled artemisinin analogue to show that the drug is mainly activated by haem and then binds covalently to over 120 proteins in the malaria parasite, affecting many of its cellular processes.