NMR structures in different membrane environments of three ocellatin peptides isolated from Leptodactylus labyrinthicus

Gomes, Karla Aparecida Guimarães Gusmão; Santos, Daniel Moreira dos; Santos, V.M.; Piló‐Veloso, Dorila; Mundim, Higor M.; Rodrigues, Leticia V.; Lião, Luciano M.; Verly, Rodrigo M.; Lima, Maria Elena de; Resende, Jarbas M.

doi:10.1016/j.peptides.2018.03.016

Cited by 15 publications

(7 citation statements)

References 70 publications

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“…While the chemical modifications of LyeTx I to LyeTx I-b and LyeTx I-b cys increased the overall amphipathic character of the biopolymer, the PEGylation process resulted in some decrease. However, direct correlations between high amphipathicity and biological activity are not readily established for AMPs, since ocellatins ( Gomes et al, 2018 ) are examples which are not highly amphipathic in nature but show pronounced membrane affinity. The activity of the PEGylated peptide can therefore be understood as the sum of different structural and chemical aspects such as: amphipathicity, net charge, presence or absence of charged residues, helical content, and the presence of chemically active moieties such as PEG.…”

Section: Discussionmentioning

confidence: 99%

PEGylation of the antimicrobial peptide LyeTx I-b maintains structure-related biological properties and improves selectivity

Brito

Carvalho

Souza

et al. 2022

Front. Mol. Biosci.

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The biological activity of antimicrobial peptides and proteins is closely related to their structural aspects and is sensitive to certain post-translational modifications such as glycosylation, lipidation and PEGylation. However, PEGylation of protein and peptide drugs has expanded in recent years due to the reduction of their toxicity. Due to their size, the PEGylation process can either preserve or compromise the overall structure of these biopolymers and their biological properties. The antimicrobial peptide LyeTx I-bcys was synthesized by Fmoc strategy and coupled to polyethylene glycol 2.0 kDa. The conjugates were purified by HPLC and characterized by MALDI-ToF-MS analysis. Microbiological assays with LyeTx I-bcys and LyeTx I-bPEG were performed against Staphylococcus aureus (ATCC 33591) and Escherichia coli (ATCC 25922) in liquid medium. MIC values of 2.0 and 1.0 µM for LyeTx I-bcys and 8.0 and 4.0 µM for LyeTx I-bPEG were observed against S. aureus and E. coli, respectively. PEGylation of LyeTx I-bcys (LyeTx I-bPEG) decreased the cytotoxicity determined by MTT method for VERO cells compared to the non-PEGylated peptide. In addition, structural and biophysical studies were performed to evaluate the effects of PEGylation on the nature of peptide-membrane interactions. Surface Plasmon Resonance experiments showed that LyeTx I-b binds to anionic membranes with an association constant twice higher than the PEGylated form. The three-dimensional NMR structures of LyeTx I-bcys and LyeTx I-bPEG were determined and compared with the LyeTx I-b structure, and the hydrodynamic diameter and zeta potential of POPC:POPG vesicles were similar upon the addition of both peptides. The mPEG-MAL conjugation of LyeTx I-bcys gave epimers, and it, together with LyeTx I-bPEG, showed clear α-helical profiles. While LyeTx I-bcys showed no significant change in amphipathicity compared to LyeTx I-b, LyeTx I-bPEG was found to have a slightly less clear separation between hydrophilic and hydrophobic faces. However, the similar conformational freedom of LyeTx I-b and LyeTx I-bPEG suggests that PEGylation does not cause significant structural changes. Overall, our structural and biophysical studies indicate that the PEGylation does not alter the mode of peptide interaction and maintains antimicrobial activity while minimizing tissue toxicity, which confirmed previous results obtained in vivo. Interestingly, significantly improved proteolytic resistance to trypsin and proteinase K was observed after PEGylation.

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Section: Discussionmentioning

confidence: 99%

PEGylation of the antimicrobial peptide LyeTx I-b maintains structure-related biological properties and improves selectivity

Brito

Carvalho

Souza

et al. 2022

Front. Mol. Biosci.

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“…The C-terminal amidated peptides were synthesized on a Rink amide resin using the Fmoc (9-fluorenylmethyloxycarbonyl) strategy as described elsewhere ( Gomes et al., 2018 ). N-terminal acetylation of Pep1 and Pep2a was promoted by the reaction of the respective peptidyl-resins with acetic anhydride before the peptide-resin cleavage.…”

Section: Methodsmentioning

confidence: 99%

Tityus serrulatus (Scorpion): From the Crude Venom to the Construction of Synthetic Peptides and Their Possible Therapeutic Application Against Toxoplasma gondii Infection

Assis

Pimentel

Reis

et al. 2021

Front. Cell. Infect. Microbiol.

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Toxoplasmosis, caused by Toxoplasma gondii, is a major public concern owing to its neurotropic nature and high morbidity and mortality rates in immunocompromised patients and newborns. Current treatment for this disease is inefficient and produces side effects. Inflammatory mediators produced during T. gondii infection (e.g., cytokines and nitric oxide) are crucial in controlling parasite replication. In this context, Tityus serrulatus venom (TsV) induces the production of inflammatory mediators by immune cells. Thus, this study aimed to isolate and identify the components of TsV with potential anti-T. gondii activity. TsV was extracted from scorpions and lyophilized or loaded onto a column to obtain its fractions. TsV subfractions were obtained using chromatography, and its amino acid sequence was identified and applied to peptide design using bioinformatics tools. The C57BL/6 mice and their harvested macrophages were used to test the anti-Toxoplasma activity of TsV components and peptides. TsV and its fraction F6 attenuated the replication of tachyzoites in macrophages and induced nitric oxide and cytokine (IL-12, TNF, and IL-6) production by infected cells, without host cell toxicity. Moreover, Su6-B toxin, a subfraction of F6, demonstrated anti-T. gondii activity. The partially elucidated and characterized amino acid sequence of Sub6-B demonstrated 93% similarity with T. serrulatus 2 toxin (Ts2). Ts2 mimetic peptides (“Pep1,” “Pep2a,” and “Pep2b”) were designed and synthesized. Pep1 and Pep2a, but not Pep2b, reduced the replication of tachyzoites in macrophages. In vivo, treatment of T. gondii-infected mice with Pep1, Pep2a, or Pep2b decreased the number of cerebral cysts and did not induce hepatotoxicity in the animals. Taken together, our data show promising immunomodulatory and antiparasitic activity of TsV that could be explored and applied in future therapies for treating infectious parasitic diseases such as toxoplasmosis.

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“…The recent increase in structural and mechanistic information on membrane‐active AMPs has opened the way for alternative approaches . Table lists 56 membrane‐active AMPs in the Protein Databank (PDB) . The structures of these peptides were solved as monomers, have well‐defined α ‐helical secondary structure and are noncyclic without internal bridging, that is bridged lactams or disulfide bonds.…”

Section: The Set Of Antimicrobial Peptides (Amps) Used In This Studymentioning

confidence: 99%

Curved or linear? Predicting the 3‐dimensional structure of α‐helical antimicrobial peptides in an amphipathic environment

et al. 2019

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α‐Helical membrane‐active antimicrobial peptides (AMPs) are known to act via a range of mechanisms, including the formation of barrel‐stave and toroidal pores and the micellisation of the membrane (carpet mechanism). Different mechanisms imply that the peptides adopt different 3D structures when bound at the water–membrane interface, a highly amphipathic environment. Here, an evolutionary algorithm is used to predict the 3D structure of a range of α‐helical membrane‐active AMPs at the water–membrane interface by optimising amphipathicity. This amphipathic structure prediction (ASP) is capable of distinguishing between curved and linear peptides solved experimentally, potentially allowing the activity and mechanism of action of different membrane‐active AMPs to be predicted. The ASP algorithm is accessible via a web interface at ://atb.uq.edu.au/asp/.

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NMR structures in different membrane environments of three ocellatin peptides isolated from Leptodactylus labyrinthicus

Cited by 15 publications

References 70 publications

PEGylation of the antimicrobial peptide LyeTx I-b maintains structure-related biological properties and improves selectivity

PEGylation of the antimicrobial peptide LyeTx I-b maintains structure-related biological properties and improves selectivity

Tityus serrulatus (Scorpion): From the Crude Venom to the Construction of Synthetic Peptides and Their Possible Therapeutic Application Against Toxoplasma gondii Infection

Curved or linear? Predicting the 3‐dimensional structure of α‐helical antimicrobial peptides in an amphipathic environment

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