Antifungal peptides with potential against pathogenic fungi

Abstract

Systemic fungal infections have increased over time due to the rise in the at-risk population, which includes immunocompromised patients, those submitted to organ transplantation or undergoing chemotherapy. Clinically available antifungals are limited since some of them have important side effects, being toxic to the host cells, and some can quell filamentous fungi, but their activity against pathogenic yeasts is not killing but controlling their multiplication. Antimicrobial peptides are multifunctional molecules expressed by several microorganisms or synthetized by different techniques. They can play a central role in infection and inflammation. Some of their other effects include chemotactic and immunomodulating activities and wound repair. Antimicrobial peptides (AMPs) can be isolated from a large variety of microorganisms, such as plants, vertebrates, insects, bacteria, and fungi. They are classified into categories according to their amino acid composition, size, and conformational structures, and naturally occurring peptides can be synthetized. Solid-phase peptide synthesis allows the use of nonproteinogenic amino acids and permits changes in structural and physicochemical properties. In these terms, peptide engineering is a useful tool to adjust features such as net charge, surface hydrophobicity, and polarity, and it may also optimize activity and overcome the limitations inherent to natural peptides. AMPs have potential applications in antifungal therapeutics in human health, and recent uses of synthetic AMPs against fungal infections are discussed in this article.