Chemoproteomic identification of molecular targets of antifungal prototypes, thiosemicarbazide and a camphene derivative of thiosemicarbazide, in Paracoccidioides brasiliensis

Abstract

Paracoccidioidomycosis (PCM) is a neglected human systemic disease caused by species of the genus Paracoccidioides. The disease attacks the host’s lungs and may disseminate to many other organs. Treatment involves amphotericin B, sulfadiazine, trimethoprim-sulfamethoxazole, itraconazole, ketoconazole, or fluconazole. The treatment duration is usually long, from 6 months to 2 years, and many adverse effects may occur in relation to the treatment; co-morbidities and poor treatment adherence have been noted. Therefore, the discovery of more effective and less toxic drugs is needed. Thiosemicarbazide (TSC) and a camphene derivative of thiosemicarbazide (TSC-C) were able to inhibit P. brasiliensis growth at a low dosage and were not toxic to fibroblast cells. In order to investigate the mode of action of those compounds, we used a chemoproteomic approach to determine which fungal proteins were bound to each of these compounds. The compounds were able to inhibit the activities of the enzyme formamidase and interfered in P. brasiliensis dimorphism. In comparison with the transcriptomic and proteomic data previously obtained by our group, we determined that TSC and TSC-C were multitarget compounds that exerted effects on the electron-transport chain and cell cycle regulation, increased ROS formation, inhibited proteasomes and peptidases, modulated glycolysis, lipid, protein and carbohydrate metabolisms, and caused suppressed the mycelium to yeast transition.

Investigation of thiosemicarbazide free or within chitosan nanoparticles in a murine model of vulvovaginal candidiasis

“…The antifungal activity of TSC has also been observed in Paracoccidioides brasiliensis. Borba et al [44] obtained similar results analyzing the potential of TSC in inhibiting the P. brasiliensis growth. TSC inhibiting ability was efficient at a concentration of 31.25 μg/mL (344 μM), presented no cytotoxic effect and a selectivity index > 15.69.…”

Beyond Melanin: Proteomics Reveals Virulence-Related Proteins in Paracoccidioides brasiliensis and Paracoccidioides lutzii Yeast Cells Grown in the Presence of L-Dihydroxyphenylalanine

“…Enrichment analyses of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways ( ) were used to functionally categorize the regulated proteins and interactions between proteins were studied on the STRING v.11 server [ 26 ], available at . Proteins associated with virulence, stress response, and pathogenesis of paracoccidioidomycosis were retrieved from indexed publications [ 9 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ] and searched into the proteomic data generated in this study. Heat maps were constructed using the GraphPad Prism 8.4.2 software.…”

One Century of Study: What We Learned about Paracoccidioides and How This Pathogen Contributed to Advances in Antifungal Therapy

“…[ 185 ]. By chemo-proteomics, Borba et al [ 186 ] suggest that thiosemi-carbazides (TSCs) and TSC-C were multitarget compounds with an effect on several essential mechanisms for Paracoccidioides such as electron-transport chain, cell cycle, ROS formation, cellular metabolisms and mycelium-yeast transition. Thus, the crucial enzymes and metabolic processes were described as potential targets of promising antifungal molecules, mainly natural compounds and synthetic derivatives.…”