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Several antimicrobial peptides (AMPs) have been reported in amphibian toxins, as temporin‐PTa from Hylarana picturata. The amino acid distribution within a helical structure of AMPs favors the design of new bioactive peptides. Therefore, this work reports the rational design of two new synthetic peptides denominated Hp‐MAP1 and Hp‐MAP2 derived from temporin‐PTa. These peptides present an amphipathic helix with positive charges of +4 and +5, hydrophobic moment (<µH>) of 0.66 and 0.72 and hydrophobicity () of 0.49 and 0.41, respectively. Hp‐MAP1 and Hp‐MAP2 displayed in vitro activity against Gram‐negative and Gram‐positive bacteria from 2.8 to 92 µM, without presenting hemolytic effects. Molecular dynamics simulation suggested that the parent and designed temporin‐like peptides lack structural stability in an aqueous solution. By contrast, α‐helical structures were predicted in hydrophobic and anionic environments. Additionally, the peptides were simulated on mimetic membranes composed of anionic and neutral phospholipids 1,2‐dipalmitoylsn‐glycerol‐3‐phosphatidylglycerol (DPPG‐anionic), 1,2‐dipalmitoyl‐sn‐lyco‐3 phosphatidylethanolamine (DPPE‐neutral). When in contact with DPPG/DPPE (90:10) and DPPG/DPPE (50:50) temporin‐PTa, Hp‐MAP1 and Hp‐MAP2 established interactions guided by hydrogen and saline bounds. Therefore, the findings described here reveal that the optimization of the amphipathic α‐helical cationic peptides Hp‐MAP1 and Hp‐MAP2 enabled the generation of new synthetic antimicrobial agents to combat pathogenic microorganisms.

The importance of neuroinflammation in neurology is becoming increasingly apparent. In addition to neuroinflammatory diseases such as multiple sclerosis, the role of neuroinflammation has been identified in many non-inflammatory neurological disorders such as stroke, epilepsy, and cancer. The immune response within the brain involves the presence of CNS resident cells; mainly glial cells, such as microglia, the CNS resident macrophages. We evaluated the peptide Ca-MAP1 bioinspired on the C. albicans immature cytolytic toxin candidalysin to develop a less hemolytic peptide with anti-neuroinflammatory, antibacterial, and cytotoxic activity against tumor cells. In silico and in vitro studies were performed at various concentrations. Ca-MAP1 exhibits low hemolytic activity at lower concentrations and was not cytotoxic to MRC-5 and BV-2 cells. Ca-MAP1 showed activity against Acinetobacter baumannii, Escherichia coli ATCC, E. coli KPC, Klebsiella pneumoniae ATCC, Pseudomonas aeruginosa, and Staphylococcus aureus ATCC. Furthermore, Ca-MAP1 exhibits anti-neuroinflammatory activity in the BV-2 microglia model, with 93.78% inhibition of nitrate production at 18.1 µM. Ca-MAP1 presents cytotoxic activity against tumor cell line NCI-H292 at 36.3 μM, with an IC50 of 38.4 µM. Ca-MAP1 demonstrates results that qualify it to be evaluated in the next steps to promote the control of infections and provide an alternative antitumor therapy.

O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais. Conselho Editorial Ciências Humanas e Sociais Aplicadas APRESENTAÇÃO A obra intitulada "Prospecção de moléculas bioativas em animais e plantas: uma visão biotecnológica" consiste em uma coletânea de artigos científicos apresentados em 9 capítulos, com enfoque em biotecnologia. Na mesma, foram expostos conhecimentos sobre bioquímica, microbiologia e bioinformática, com estudos em diferentes espécies, abrangendo a biodiversidade brasileira. Na biotecnologia, os campos de estudos são muito amplos e englobam pesquisas complexas envolvendo microrganismos, plantas e animais. Desta forma, a obra apresenta pesquisas sobre moléculas bioativas derivadas de aracnídeos, insetos, répteis, anfíbios e plantas. Essas moléculas bioativas apresentam uma gama de atividades biológicas, e algumas dessas, com potencial antimicrobiano, inibidores de peptidases, entre outras, foram apresentadas no decorrer da obra. Ademais, moléculas protéicas bioativas provenientes de fontes naturais, podem ter sua sequencias primárias caracterizadas e modificada por meio da bioinformática (metodologia de desenho racional), que busca melhorar seu potencial terapêutico in vitro partindo de estudos in silico. As informações geradas nesta obra são de extrema relevância em nível acadêmico, pois mostra pesquisas básicas avançando para pesquisas aplicadas, o que proporciona o enriquecimento da comunidade científica e formação profissional de alunos de graduação e pós graduação.

In recent years, antimicrobial peptides isolated from amphibian toxins have gained attention as new multifunctional drugs interacting with different molecular targets. We aimed to rationally design a new peptide from temporin-PTa. Hp-MAP3 (NH2-LLKKVLALLKKVL-COOH), net charge (+4), hydrophobicity (0.69), the content of hydrophobic residues (69%), and hydrophobic moment (0.73). For the construction of the analog peptide, the physicochemical characteristics were reorganized into hydrophilic and hydrophobic residues with the addition of lysines and leucines. The minimum inhibitory concentration was 2.7 to 43 μM against the growth of Gram-negative and positive bacteria, and the potential for biofilm eradication was 173.2 μM. Within 20 min, the peptide Hp-MAP3 (10.8 μM) prompted 100% of the damage to E. coli cells. At 43.3 μM, eliminated 100% of S. aureus within 5 min. The effects against yeast species of the Candida genus ranged from 5.4 to 86.6 μM. Hp-MAP3 presents cytotoxic activity against tumor HeLa at a concentration of 21.6 μM with an IC50 of 10.4 µM. Furthermore, the peptide showed hemolytic activity against murine erythrocytes. Structural studies carried out by circular dichroism showed that Hp-MAP3, while in the presence of 50% trifluoroethanol or SDS, an α-helix secondary structure. Finally, Amphipathic Hp-MAP3 building an important model for the design of new multifunctional molecules.

The need for discovering new compounds that can act selectively on pathogens is becoming increasingly evident, given the number of deaths worldwide due to bacterial infections or tumor cells. New multifunctional biotechnological tools are being sought, including compounds present in spider venoms, which have high biotechnological potential. The present work aims to perform the rational design and functional evaluation of synthetic peptides derived from Lachesana tarabaevi spider toxin, known as latarcin-3a. The antimicrobial activity was tested against Gram-positive and -negative bacteria, with minimum inhibitory concentrations (MIC) between 4 and 128 μg.ml−1. Anti-biofilm tests were then performed to obtain MICs, where the peptides demonstrated activity from 4 to 128 μg.ml−1. In vitro cell cytotoxicity assays were carried out from tumor cell lines, lineages C1498, Kasumi-1, K-562, Jurkat, MOLT4, and Raji. Erythrocyte integrity was evaluated in the presence of synthetic peptides analog, which did not promote hemolysis at 128 μg.ml−1. The peptide that showed the best antibacterial activity was Lt-MAP3 and the best antitumor was Lt-MAP2. In conclusion, rational design of multifunctional antimicrobial peptides may be promising alternative tools in the treatment of emerging diseases such as bacterial infections and tumor cells.

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