Polypeptides Targeting Paracoccidioides brasiliensis Drk1

Area of Science:

• Mycology
• Molecular Biology
• Drug Discovery

Background:

• Conventional treatments for paracoccidioidomycosis are toxic and require prolonged regimens.
• The dimorphic fungus *Paracoccidioides* spp. must transition from mycelial to yeast form for infection establishment.
• The fungal Drk1 protein is crucial for this morphological shift and virulence.

Purpose of the Study:

• To identify novel therapeutic targets for paracoccidioidomycosis.
• To explore the role of the PbDrk1 protein in *Paracoccidioides brasiliensis* virulence.
• To develop peptide-based inhibitors of fungal pathobiology.

Main Methods:

• Phage-display technology to identify peptides binding to PbDrk1.
• Assessment of peptide effects on *P. brasiliensis* morphology, adhesion, and cell wall composition.
• Evaluation of peptide efficacy in a *Galleria mellonella* infection model.

Main Results:

• Identified peptides inhibited the mycelial-to-yeast phase transition in *P. brasiliensis*.
• Peptides reduced fungal adhesion to pneumocytes and modulated cell wall glycosylation.
• Peptide treatment enhanced survival rates in *Galleria mellonella* larvae.

Conclusions:

• PbDrk1 is a promising target for developing new therapies against paracoccidioidomycosis.
• Peptides targeting PbDrk1 can inhibit key virulence factors and potentiate existing antifungal drugs.
• Further investigation of PbDrk1's function could lead to innovative treatment strategies.