Repurposing FDA-Approved Drugs to Inhibit Fungal PPTases for Broad-Spectrum Synergy

Fungal secondary metabolites serve as crucial virulence effectors; however, the potential of their biosynthetic pathways as antifungal targets remains inadequately comprehended. In this study, we put forward a novel antifungal strategy that targets the conserved global secondary metabolic pathway in pathogenic fungi. Through genome mining, phylogenetic analysis, and structural modeling, we identified invariant residues in phosphopantetheinyl transferases (PPTases), which are essential for secondary metabolism, and revealed them as pan-fungal targets. High-throughput screening indicated that the FDA-approved tepotinib and eltrombopag bind to PPTases to interfere with mycotoxin biosynthesis, thereby reducing the fungal burden and alleviating lung inflammation in a mouse model of pulmonary aspergillosis. These compounds exhibited broad-spectrum activity against common pathogens, including Aspergillus fumigatus, Mucor circinelloides, Aspergillus flavus, Fusarium oxysporum, Cryptococcus neoformans, and Cryptococcus gattii. Notably, both drug candidates demonstrated synergistic effects with amphotericin B, reducing its half-maximal inhibitory concentration by 7.4- and 2.6-fold, respectively. This research provides a metabolic targeting framework and paves new paths for the rational design of broad-spectrum antifungals and combination therapies.