Uma breve revisão: aspectos metodológicos e estruturais de peptídeos antimicrobianos (PAMs) de fungos filamentosos e suas aplicações biotecnológicas.

Abstract

Antimicrobial peptides (AMPs) are small proteins that have activity against invaders or that compete for the same survival environment. AMPs are usually composed of 10 to 50 amino acids, with an overall positive charge, ranging from +2 to +11, most often in the α-helix or ẞ-sheet conformation. Among similar producers are filamentous fungi, the phylum Ascomycota possesses the majority of producers. The production of AMPs (called AFPs) by the genus Aspergillus and Penicillium stands out. Studies have been undertaken with the purpose of growing the levels of AFPs production and its expression, in a way that is possible to evaluate the molecules structurally and to understand the factors that lead to biological activity. This work aimed to present, through literature review, the biochemical characteristics, the techniques of production, and purification of the main AFP, produced by filamentous fungus described in the literature, with emphasis on Aspergillus and Penicillium genera, as well as the application of these proteins. A search for articles and information was carried out in the PubMed database, Portal de Periódicos da Capes and Proteins of the National Center of Biotechnology Information (NCBI), retrieving articles between the period of 1965 and 2021. Currently, there is a production of AFP by culturing the organism in a specific culture media that induces the fungus to the desired product, and by means of an expression system based on the P. chrysogenum. The purification of the peptides occurs mainly through chromatographic techniques, usually ion exchange due to the cationic nature of the peptides. Once produced and purified, AFPs have the possibility of being explored in terms of their structure and application. The chitin-binding sequence (in peptides of Aspergillus genus), the γ-core motif, the disulfide bonds and the positive charge are highlighted as key structures of these molecules, allowing the use of these proteins in the fight against fungal infection in agriculture and in the human body. Since the difficulty in isolating AFPs due to the lack of expression of these molecules or the expression at low levels seems to have been overcome by genetic engineering, possibly the transition to in vivo and large-scale studies is the biggest challenge today, since the studies for the application of AFPs remain at the laboratory level (in vitro), wich requires not only studies that elucidate the structure and function of these proteins, but also efforts that allow the arrival of AFPs in the industry.