Many bacterial and viral pathogens (or their toxins), including Pseudomonas aeruginosa exotoxin A, require processing by host pro-protein convertases such as furin to cause dis- ease. We report the development of a novel irreversible inhibitor of furin (QUB-F1) consist- ing of a diphenyl phosphonate electrophilic warhead coupled with a substrate-like peptide (RVKR), that also includes a biotin tag, to facilitate activity-based profiling/visualisation. QUB-F1 displays greater selectivity for furin, in comparison to a widely used exemplar com- pound (furin I) which has a chloromethylketone warhead coupled to RVKR, when tested against the serine trypsin-like proteases (trypsin, prostasin and matriptase), factor Xa and the cysteine protease cathepsin B. We demonstrate QUB-F1 does not prevent P. aerugi- nosa exotoxin A-induced airway epithelial cell toxicity; in contrast to furin I, despite inhibiting cell surface furin-like activity to a similar degree. This finding indicates additional proteases, which are sensitive to the more broad-spectrum furin I compound, may be involved in this process.
- protease inhibitor
- pseudomonas aeruginosa exotoxin
- serine proteases
Ferguson, T. E. G., Reihill, J. A., Walker, B., Hamilton, R. A., & Martin, S. L. (2016). A Selective Irreversible Inhibitor of Furin Does Not Prevent Pseudomonas Aeruginosa Exotoxin A-Induced Airway Epithelial Cytotoxicity. PLoS ONE, 11(7), [e0159868]. https://doi.org/10.1371/journal.pone.0159868