Cherchez l'Electron

4 years ago

Cherchez l'Electron

Pascal Mäser

Who wouldn't want to have a drug that is activated only in the target cell? Prodrugs that are metabolically triggered inside the pathogen but not in the host are an attractive concept in antimicrobial chemotherapy. Of particular interest are bioreductive prodrugs such as nitro compounds or quinones that can initiate cytotoxic redox cascades and release active metabolites. The critical points for the selectivity of such molecules are, what is the source of the electrons that activate the prodrug, and which are the enzymes that catalyze the reduction? In this issue, Meredith et al. conceive an elegant approach to answer these questions, making use of reverse genetics in Trypanosoma brucei. By overexpression of key reductase genes, they engineer trypanosomal indicator lines that are hypersensitive to particular bioreductive prodrugs and allow to discriminate between one-electron and two-electron transfer activation mechanisms. Indicator lines that are also defective in DNA repair further indicate whether the resultant metabolites interfere with the parasite's genome. This set of T. brucei indicator lines provides a tool for the deconvolution of the mechanisms of prodrug activation and drug action that will facilitate the rational development of bioreductive prodrugs for parasite chemotherapy. This article is protected by copyright. All rights reserved. Bioreductive prodrugs are activated inside the pathogen by the acquisition of electrons. This microcommentary gives an overview on the paper by Meredith et al., who have engineered Trypanosoma brucei indicator lines to deconvolute the mechanisms of prodrug activation and drug action of aziridinyl benzoquinones.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1111/mmi.13773