Diaz-Roa, A. | bioRxiv Science

bioRxiv2022

How a tarantula can help treat infections: Avicularia juruensis theraphotoxins that also act as antimicrobials.

Short abstractConsidering that there are still many species little-studied, this work aimed to analyze the venom of the spider Avicularia juruensis searching for antimicrobial peptides. Using reverse-phase high-performance liquid chromatography, microbial growth inhibition assay, transcriptomics, and proteomics approaches we identified three antimicrobial peptides: Avilin, Juruin_2, and Juruenine. All of them showed similarities with neurotoxins that act on ion channels and, probably, they have the ICK motif. The study of animal venoms is of great importance to carry out the characterization of unknown components and that may have a biotechnological application, in special venoms from spiders that are from less studied families. Spiders are the most successful group of venomous animals, comprising more than 50,350 species distributed in all terrestrial habitats. One strategy that facility their broad distribution is the production of elaborate venoms, which are composed of inorganic salts, organic molecules with low molecular mass, free amino acids, small polypeptides, linear peptides, nucleotides, disulfide-rich peptides, enzymes, and high molecular mass proteins. Considering that there are still many species little-studied, this work aimed to analyze the venom of the mygalomorph spider Avicularia juruensis searching for new antimicrobial peptides. Using reverse-phase high-performance liquid chromatography, microbial growth inhibition assay, transcriptomics, and proteomics approaches we identified three antimicrobial peptides that were named Avilin, Juruin_2, and Juruenine. All of them showed similarities with neurotoxins that act on ion channels and, probably, they have the ICK motif in their structure. The ICK fold seems to be conserved in several venomous animal lineages and presents elevated functional diversity, as well as gives stability to the toxins. The study of animal venoms is of great importance to carry out the characterization of unknown components and that may have a biotechnological application (like the antimicrobial peptides), in special venoms from spiders that are from less studied families.

microbiology↗

bioRxiv2022

Doderlin: Isolation and Characterization of a Broad-Spectrum Antimicrobial Peptide from Lactobacillus acidophilus

Lactobacillus acidophilus are Gram-positive bacteria distributed in diverse environments, and as being a component of the normal microbiota of gastrointestinal and urogenital tract, being relevant to humans. Classified as lactic acid bacteria, due to the pro-duction of lactic acid, Lactobacillus can also produce antimicrobial peptides (AMPs), which is a compound synthesized by all forms of life aiming for protecting themselves from threats and to increase their competitivity to survive in a specific environment. AMPs are molecules capable of inhibiting the growth of microorganisms and, due to the indiscriminate use of conventional antibiotics and the emergence of multi-resistant bacteria, they have become an alternative, not only for treating multi-resistant infections, but also for probiotic product confection and food conservation. Considering the rampant rise of resistance, the present study aimed to isolate and characterize antimicrobial peptides from Lactobacillus acidophilus extracts. Samples were obtained from Lactobacillus acid extract supernatant which was pre-fractionated on disposable cartridges, followed by a high-performance liquid chromatography (HPLC). The collected fractions were evaluated in a liquid growth inhibition assay where eight fractions antimicrobial activity were obtained. One of them was selected for further characterization by mass spectrometry (MS), due to its antimicrobial activity against Candida albicans and conclusive results in mass spectrometry analysis. This molecule was identified as a peptide having a molecular mass of 1788.01 Da, peptide sequence NEPTHLLKAFSKAGFQ, and named Doderlin. Interestingly, antimicrobial molecules isolated from L. acidophilus have already been described previously, but few reports in the literature describe an AMP effective against C. albicans as reported here. The results obtained suggest that this newly discovered molecule have a biological property with potential to be applied in pharmaceutical and food companies in the fight against contamination and/or for treating infections caused by microorganisms. IMPORTANCEDoderlin, this newly discovered molecule have a biological property with potential to be applied in pharmaceutical and food companies in the fight against contamination and/or for treating infections caused by microorganisms.

microbiology↗