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Special Issue "Antimicrobial Peptides and Peptidomimetics"

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Bioorganic Chemistry".

Deadline for manuscript submissions: closed (31 May 2018)

Special Issue Editor

Guest Editor
Assoc. Prof. Steven L. Cobb

Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK
Website 1 | Website 2 | E-Mail
Interests: chemical-biology of peptides; organic synthesis; peptide and peptoid chemistry; bio-organic fluorine chemistry; bio-conjugation; drug target validation; infectious disease and neglected tropical diseases

Special Issue Information

Dear Colleagues,

Our ability to treat what we currently consider minor bacterial infections underpins all of modern medicine and the future cost of failure to treat such infections is enormous both in terms of societal and economic impacts. The situation is exacerbated by the fact that the number of new antibiotics being brought to market is at an all-time low. There is an urgent need for new antibiotics that can be used to treat the rapid emergence of antimicrobial resistance.

The effectiveness of the innate immune system in providing the first line of defence against infection, has led main research groups around the world to investigate the activities of antimicrobial peptides (AMPs), with a view to their use as templates for the design of innovative therapeutics to combat emerging antimicrobial resistance. However, despite their considerable promise in terms of biological activity, efforts to develop AMPs as generic antibiotics have been hampered by their inherent chemical instability and susceptibility to enzymatic degradation. Only a handful of AMPs are currently in clinical trials.

This Special Issue is aimed at covering recent advances in the synthesis, mechanistic understanding and applications of antimicrobial peptides (and peptidomimetics) in the development of new agents for the treatment of microbial infections.  

Assoc. Prof. Steven L Cobb
Guest Editor

Manuscript Submission Information

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Keywords

  • Microbial Infection (bacterial, fungal and parasitic)
  • Antimicrobial Peptides
  • Peptoids
  • Peptidomimetics
  • Synthesis
  • Mode of action
  • Structure and properties
  • Biophysics

Published Papers (13 papers)

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Research

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Open AccessArticle HJH-1, a Broad-Spectrum Antimicrobial Activity and Low Cytotoxicity Antimicrobial Peptide
Molecules 2018, 23(8), 2026; https://doi.org/10.3390/molecules23082026
Received: 23 July 2018 / Revised: 8 August 2018 / Accepted: 13 August 2018 / Published: 14 August 2018
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Abstract
With the overuse of antibiotics, multidrug-resistant bacteria pose a significant threat to human health. Antimicrobial peptides (AMPs) are a promising alternative to conventional antibiotics. This study examines the antimicrobial and membrane activity of HJH-1, a cationic peptide derived from the hemoglobin α-subunit of
[...] Read more.
With the overuse of antibiotics, multidrug-resistant bacteria pose a significant threat to human health. Antimicrobial peptides (AMPs) are a promising alternative to conventional antibiotics. This study examines the antimicrobial and membrane activity of HJH-1, a cationic peptide derived from the hemoglobin α-subunit of bovine erythrocytes P3. HJH-1 shows potent antimicrobial activity against different bacterial species associated with infection and causes weaker hemolysis of erythrocytes, at least five times the minimum inhibitory concentration (MIC). HJH-1 has good stability to tolerance temperature, pH value, and ionic strength. The anionic membrane potential probe bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC4(3)] and propidium iodide are used as indicators of membrane integrity. In the presence of HJH-1 (1× MIC), Escherichia coli membranes rapidly depolarise, whereas red blood cells show gradual hyperpolarisation. Scanning electron microscopy and transmission electron micrographs show that HJH-1 (1× MIC) damaged the membranes of Escherichia coli, Staphylococcus aureus, and Candida albicans. In conclusion, HJH-1 damages the integrity of the bacterial membrane, preventing the growth of bacteria. HJH-1 has broad-spectrum antibacterial activity, and these activities are performed by changing the normal cell transmembrane potential and disrupting the integrity of the bacterial membrane. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessArticle Isolation and Evaluation of Bioactive Protein and Peptide from Domestic Animals’ Bone Marrow
Molecules 2018, 23(7), 1673; https://doi.org/10.3390/molecules23071673
Received: 9 June 2018 / Revised: 29 June 2018 / Accepted: 2 July 2018 / Published: 9 July 2018
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Abstract
In this work, proteins and peptides were isolated from four kinds of animal bone marrow and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and liquid chromatography-mass spectrometry (LC/MS). The antimicrobial and antioxidant activity
[...] Read more.
In this work, proteins and peptides were isolated from four kinds of animal bone marrow and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and liquid chromatography-mass spectrometry (LC/MS). The antimicrobial and antioxidant activity of these proteins were investigated in vitro. The nutritional value was evaluated by analyzing their free amino acid composition. The results indicates that all of the extracts appeared two bands at SDS-PAGE, the peptide band at 4.1–10 kDa and protein band at 66 kDa, these data are consistent with LC/MS results. FT-IR analysis showed that the secondary structure of protein mainly consists of α-helix. SEM micrographs revealed that the fractions have different morphological characteristics. Horse bone marrow protein (HBMP) showed the highest antioxidant activity to DPPH free radical, IC50 value was 0.573 mg/mL. Most of the obtained fractions showed antimicrobial activities towards Escherichia coli (EC) and Candida albicans (CA). Total free amino acid content ranged between 5.15–49.60 mg/g, and among them, HBMP displayed the highest abundance, 49.7 mg/g, which amino acid composition ratio approached the Food and Agriculture Organization/World Health Organization (FAO/WHO) ideal amino acid pattern recommendation. This study provides fundamental knowledge and a basic study method for the research into and development of animal bone marrow proteins and peptides as functional food and drug resources. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessFeature PaperArticle Synthesis of Antibacterial Nisin–Peptoid Hybrids Using Click Methodology
Molecules 2018, 23(7), 1566; https://doi.org/10.3390/molecules23071566
Received: 31 May 2018 / Revised: 18 June 2018 / Accepted: 21 June 2018 / Published: 28 June 2018
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Abstract
Antimicrobial peptides and structurally related peptoids offer potential for the development of new antibiotics. However, progress has been hindered by challenges presented by poor in vivo stability (peptides) or lack of selectivity (peptoids). Herein, we have developed a process to prepare novel hybrid
[...] Read more.
Antimicrobial peptides and structurally related peptoids offer potential for the development of new antibiotics. However, progress has been hindered by challenges presented by poor in vivo stability (peptides) or lack of selectivity (peptoids). Herein, we have developed a process to prepare novel hybrid antibacterial agents that combine both linear peptoids (increased in vivo stability compared to peptides) and a nisin fragment (lipid II targeting domain). The hybrid nisin–peptoids prepared were shown to have low micromolar activity (comparable to natural nisin) against methicillin-resistant Staphylococcus aureus. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessArticle Antifungal Activity of an Abundant Thaumatin-Like Protein from Banana against Penicillium expansum, and Its Possible Mechanisms of Action
Molecules 2018, 23(6), 1442; https://doi.org/10.3390/molecules23061442
Received: 7 May 2018 / Revised: 25 May 2018 / Accepted: 29 May 2018 / Published: 14 June 2018
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Abstract
Thaumatin-like protein from banana (designated BanTLP) has been purified by employing a simple protocol consisting of diethylaminoethyl Sephadex (DEAE–Sephadex) chromatography, gel filtration on Sephadex G50, and reversed-phase chromatography. The purified protein was identified by MALDI-TOF mass spectrometry, with an estimated molecular weight of
[...] Read more.
Thaumatin-like protein from banana (designated BanTLP) has been purified by employing a simple protocol consisting of diethylaminoethyl Sephadex (DEAE–Sephadex) chromatography, gel filtration on Sephadex G50, and reversed-phase chromatography. The purified protein was identified by MALDI-TOF mass spectrometry, with an estimated molecular weight of 22.1 kDa. BanTLP effectively inhibited in vitro spore germination of Penicillium expansum, one of the main postharvest pathogens in fruits. This study further investigated the antifungal properties and underlying mechanisms of BanTLP against P. expansum. Results demonstrated that BanTLP exhibited antifungal activity in a wide pH range (4.0–10.0) at 20–50 °C. Propidium iodide (PI) influx and potassium release confirmed that BanTLP induced membrane disruption of the test pathogen, increasing the membrane permeability and disintegration of the cell. This led to cell death, as evidenced by the assays of thiobarbituric acid-reactive species (TBARS) content, the production of reactive oxygen species (ROS), and 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence integrity. Ultrastructural alterations in P. expansum conidia after BanTLP treatment revealed severe damage to the cell wall. These results suggest that BanTLP purified from banana exerts antifungal activity against P. expansum by inducing plasma membrane disturbance and cell wall disorganization. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessArticle In Vitro ADME Properties of Two Novel Antimicrobial Peptoid-Based Compounds as Potential Agents against Canine Pyoderma
Molecules 2018, 23(3), 630; https://doi.org/10.3390/molecules23030630
Received: 17 January 2018 / Revised: 28 February 2018 / Accepted: 5 March 2018 / Published: 10 March 2018
Cited by 1 | PDF Full-text (1849 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Antimicrobial peptides (AMPs) hold promise as the next generation of antimicrobial agents, but often suffer from rapid degradation in vivo. Modifying AMPs with non-proteinogenic residues such as peptoids (oligomers of N-alkylglycines) provides the potential to improve stability. We have identified two novel
[...] Read more.
Antimicrobial peptides (AMPs) hold promise as the next generation of antimicrobial agents, but often suffer from rapid degradation in vivo. Modifying AMPs with non-proteinogenic residues such as peptoids (oligomers of N-alkylglycines) provides the potential to improve stability. We have identified two novel peptoid-based compounds, B1 and D2, which are effective against the canine skin pathogen Staphylococcus pseudintermedius, the main cause of antibiotic use in companion animals. We report on their potential to treat infections topically by characterizing their release from formulation and in vitro ADME properties. In vitro ADME assays included skin penetration profiles, stability to proteases and liver microsomes, and plasma protein binding. Both B1 and D2 were resistant to proteases and >98% bound to plasma proteins. While half-lives in liver microsomes for both were >2 h, peptoid D2 showed higher stability to plasma proteases than the peptide-peptoid hybrid B1 (>2 versus 0.5 h). Both compounds were suitable for administration in an oil-in-water cream formulation (50% release in 8 h), and displayed no skin permeation, in the absence or presence of skin permeability modifiers. Our results indicate that these peptoid-based drugs may be suitable as antimicrobials for local treatment of canine superficial pyoderma and that they can overcome the inherent limitations of stability encountered in peptides. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessArticle Antibacterial and Antifungal Activities of Poloxamer Micelles Containing Ceragenin CSA-131 on Ciliated Tissues
Molecules 2018, 23(3), 596; https://doi.org/10.3390/molecules23030596
Received: 5 February 2018 / Revised: 25 February 2018 / Accepted: 2 March 2018 / Published: 7 March 2018
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Abstract
Ceragenins were designed as non-peptide mimics of endogenous antimicrobial peptides, and they display broad-spectrum antibacterial and antifungal activities, including the ability to eradicate established biofilms. These features of ceragenins make them attractive potential therapeutics for persistent infections in the lung, including those associated
[...] Read more.
Ceragenins were designed as non-peptide mimics of endogenous antimicrobial peptides, and they display broad-spectrum antibacterial and antifungal activities, including the ability to eradicate established biofilms. These features of ceragenins make them attractive potential therapeutics for persistent infections in the lung, including those associated with cystic fibrosis. A characteristic of an optimal therapeutic for use in the lungs and trachea is the exertion of potent antimicrobial activities without damaging the cilia that play a critical role in these tissues. In previous work, potent antimicrobial activities of ceragenin CSA-131 have been reported; however, we found in ex vivo studies that this ceragenin, at concentrations necessary to eradicate established biofilms, also causes loss of cilia function. By formulating CSA-131 in poloxamer micelles, cilia damage was eliminated and antimicrobial activity was unaffected. The ability of CSA-131, formulated with a poloxamer, to reduce the populations of fungal pathogens in tracheal and lung tissue was also observed in ex vivo studies. These findings suggest that CSA-131, formulated in micelles, may act as a potential therapeutic for polymicrobial and biofilm-related infections in the lung and trachea. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessArticle Role of Cationic Side Chains in the Antimicrobial Activity of C18G
Molecules 2018, 23(2), 329; https://doi.org/10.3390/molecules23020329
Received: 11 January 2018 / Revised: 23 January 2018 / Accepted: 1 February 2018 / Published: 4 February 2018
Cited by 4 | PDF Full-text (3496 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Antimicrobial peptides (AMPs) have been an area of great interest, due to the high selectivity of these molecules toward bacterial targets over host cells and the limited development of bacterial resistance to these molecules throughout evolution. The peptide C18G has been shown to
[...] Read more.
Antimicrobial peptides (AMPs) have been an area of great interest, due to the high selectivity of these molecules toward bacterial targets over host cells and the limited development of bacterial resistance to these molecules throughout evolution. The peptide C18G has been shown to be a selective, broad spectrum AMP with a net +8 cationic charge from seven lysine residues in the sequence. In this work, the cationic Lys residues were replaced with other natural or non-proteinogenic cationic amino acids: arginine, histidine, ornithine, or diaminopropionic acid. These changes vary in the structure of the amino acid side chain, the identity of the cationic moiety, and the pKa of the cationic group. Using a combination of spectroscopic and microbiological methods, the influence of these cationic groups on membrane binding, secondary structure, and antibacterial activity was investigated. The replacement of Lys with most other cationic residues had, at most, 2-fold effects on minimal inhibitory concentration against a variety of Gram-positive and Gram-negative bacteria. However, the peptide containing His as the cationic group showed dramatically reduced activity. All peptide variants retained the ability to bind lipid vesicles and showed clear preference for binding vesicles that contained anionic lipids. Similarly, all peptides adopted a helical conformation when bound to lipids or membrane mimetics, although the peptide containing diaminopropionic acid exhibited a decreased helicity. The peptides exhibited a wider variety of activity in the permeabilization of bacterial membranes, with peptides containing Lys, Arg, or Orn being the most broadly active. In all, the antibacterial activity of the C18G peptide is generally tolerant to changes in the structure and identity of the cationic amino acids, yielding new possibilities for design and development of AMPs that may be less susceptible to immune and bacterial recognition or in vivo degradation. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessArticle In Vitro Evaluation of Cytotoxicity and Permeation Study on Lysine- and Arginine-Based Lipopeptides with Proven Antimicrobial Activity
Molecules 2017, 22(12), 2173; https://doi.org/10.3390/molecules22122173
Received: 14 November 2017 / Revised: 4 December 2017 / Accepted: 6 December 2017 / Published: 8 December 2017
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Abstract
Owing to their excellent antimicrobial activities with a relatively low cost of production, lipopeptides are being intensively investigated as potential alternatives to popular antimicrobials. However, a critical obstacle for their application is a relatively high toxicity, hence a lot of attention has been
[...] Read more.
Owing to their excellent antimicrobial activities with a relatively low cost of production, lipopeptides are being intensively investigated as potential alternatives to popular antimicrobials. However, a critical obstacle for their application is a relatively high toxicity, hence a lot of attention has been paid to designing new molecules with optimal properties. In this study we synthesized the following lipopeptides: C16-KK-NH2, C16-KεK-NH2, C16-KKK-NH2, C16-KRK-NH2, C16-RR-NH2, C16-RRR-NH2, (C10)2-KKKK-NH2 and (C12)2-KKKK-NH2. Their antimicrobial activity against representative strains of Gram-positive bacteria, Gram-negative bacteria and fungi has been confirmed. The compounds have been evaluated with regard to the safety of their application in dermatology. The cytotoxicity was determined in HaCaT keratinocytes using MTT assay, whereas Strat M membranes placed in Franz diffusion cells were used to assess their ability to skin permeation. The compounds containing one hexadecanoic acid chain turned out to be very toxic towards human keratinocytes, while lipopeptides containing two fatty acid chains (decanoic and dodecanoic) demonstrated much lower cytotoxicity. For the most promising lipopeptide, (C10)2-KKKK-NH2, the measured IC50 on HaCaT keratinocytes was few times higher as compared to MICs obtained for the tested bacteria. Both groups of lipopeptides did not permeate the model membranes and therefore lack of permeation through human skin could be expected. The results of this work encourage further research on the potential application of lipopeptides with two fatty acids as novel antimicrobials. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
Open AccessArticle Design, Recombinant Fusion Expression and Biological Evaluation of Vasoactive Intestinal Peptide Analogue as Novel Antimicrobial Agent
Molecules 2017, 22(11), 1963; https://doi.org/10.3390/molecules22111963
Received: 12 October 2017 / Accepted: 8 November 2017 / Published: 14 November 2017
Cited by 2 | PDF Full-text (4734 KB) | HTML Full-text | XML Full-text
Abstract
Antimicrobial peptides represent an emerging category of therapeutic agents with remarkable structural and functional diversity. Modified vasoactive intestinal peptide (VIP) (VIP analogue 8 with amino acid sequence “FTANYTRLRRQLAVRRYLAAILGRR”) without haemolytic activity and cytotoxicity displayed enhanced antimicrobial activities against Staphylococcus aureus (S. aureus
[...] Read more.
Antimicrobial peptides represent an emerging category of therapeutic agents with remarkable structural and functional diversity. Modified vasoactive intestinal peptide (VIP) (VIP analogue 8 with amino acid sequence “FTANYTRLRRQLAVRRYLAAILGRR”) without haemolytic activity and cytotoxicity displayed enhanced antimicrobial activities against Staphylococcus aureus (S. aureus) ATCC 25923 and Escherichia coli (E. coli) ATCC 25922 than parent VIP even in the presence of 180 mM NaCl or 50 mM MgCl2, or in the range of pH 4–10. VIP analogue 8 was expressed as fusion protein thioredoxin (Trx)-VIP8 in E. coli BL21(DE) at a yield of 45.67 mg/L. The minimum inhibitory concentration (MIC) of the recombinant VIP analogue 8 against S. aureus ATCC 25923 and E. coli ATCC 25922 were 2 μM. These findings suggest that VIP analogue 8 is a promising candidate for application as a new and safe antimicrobial agent. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessArticle PSN-PC: A Novel Antimicrobial and Anti-Biofilm Peptide from the Skin Secretion of Phyllomedusa-camba with Cytotoxicity on Human Lung Cancer Cell
Molecules 2017, 22(11), 1896; https://doi.org/10.3390/molecules22111896
Received: 17 October 2017 / Revised: 30 October 2017 / Accepted: 2 November 2017 / Published: 7 November 2017
Cited by 2 | PDF Full-text (4483 KB) | HTML Full-text | XML Full-text
Abstract
Peptides derived from amphibian skin secretion are promising drug prototypes for combating widespread infection. In this study, a novel peptide belonging to the phylloseptin family of antimicrobial peptides was isolated from the skin secretion of the Phyllomedusa camba, namely phylloseptin-PC (PSN-PC). The
[...] Read more.
Peptides derived from amphibian skin secretion are promising drug prototypes for combating widespread infection. In this study, a novel peptide belonging to the phylloseptin family of antimicrobial peptides was isolated from the skin secretion of the Phyllomedusa camba, namely phylloseptin-PC (PSN-PC). The biosynthetic precursor was obtained by molecular cloning and the mature peptide sequence was confirmed through tandem mass spectrometry (MS/MS) fragmentation sequencing in the skin secretion. The synthetic replicate exhibited a broad spectrum antimicrobial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans at concentrations of 2, 2, 8, 32 and 2 µM, respectively. It also showed the capability of eliminating S. aureus biofilm with a minimal biofilm eradication concentration of 8 µM. The haemolysis of this peptide was not significant at low concentrations but had a considerable increase at high concentrations. Additionally, this peptide showed an anti-proliferation effect on the non-small cell lung cancer cell line (NCI-H157), with low cytotoxicity on the human microvascular endothelial cell line (HMEC-1). The discovery of the novel peptide may provide useful clues for new drug discoveries. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessArticle Tryptophan-Containing Cyclic Decapeptides with Activity against Plant Pathogenic Bacteria
Molecules 2017, 22(11), 1817; https://doi.org/10.3390/molecules22111817
Received: 2 October 2017 / Revised: 25 October 2017 / Accepted: 25 October 2017 / Published: 26 October 2017
Cited by 1 | PDF Full-text (1756 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A library of 66 cyclic decapeptides incorporating a Trp residue was synthesized on solid phase and screened against the phytopathogenic bacteria Pseudomonas syringae pv. syringae, Xanthomonas axonopodis pv. vesicatoria, and Erwinia amylovora. The hemolytic activity of these peptides was also evaluated.
[...] Read more.
A library of 66 cyclic decapeptides incorporating a Trp residue was synthesized on solid phase and screened against the phytopathogenic bacteria Pseudomonas syringae pv. syringae, Xanthomonas axonopodis pv. vesicatoria, and Erwinia amylovora. The hemolytic activity of these peptides was also evaluated. The results obtained were compared with those of a collection of Phe analogues previously reported. The analysis of the data showed that the presence of the Trp improved the antibacterial activity against these three pathogens. In particular, 40 to 46 Trp analogues displayed lower minimum inhibitory concentration (MIC) values than their corresponding Phe counterparts. Interestingly, 26 Trp-containing sequences exhibited MIC of 0.8 to 3.1 μM against X. axonopodis pv. vesicatoria, 21 peptides MIC of 1.6 to 6.2 μM against P. syringae pv. syringae and six peptides MIC of 6.2 to 12.5 μM against E. amylovora. Regarding the hemolysis, in general, Trp derivatives displayed a percentage of hemolysis comparable to that of their Phe analogues. Notably, 49 Trp-containing cyclic peptides showed a hemolysis ≤ 20% at 125 μM. The peptides with the best biological activity profile were c(LKKKLWKKLQ) (BPC086W) and c(LKKKKWLLKQ) (BPC108W), which displayed MIC values ranging from 0.8 to 12.5 μM and a hemolysis ≤ 8% at 125 μM. Therefore, it is evident that these Trp sequences constitute promising candidates for the development of new agents for use in plant protection. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Review

Jump to: Research

Open AccessReview Antimicrobial Peptides: Powerful Biorecognition Elements to Detect Bacteria in Biosensing Technologies
Molecules 2018, 23(7), 1683; https://doi.org/10.3390/molecules23071683
Received: 4 June 2018 / Revised: 6 July 2018 / Accepted: 9 July 2018 / Published: 10 July 2018
PDF Full-text (5792 KB) | HTML Full-text | XML Full-text
Abstract
Bacterial infections represent a serious threat in modern medicine. In particular, biofilm treatment in clinical settings is challenging, as biofilms are very resistant to conventional antibiotic therapy and may spread infecting other tissues. To address this problem, biosensing technologies are emerging as a
[...] Read more.
Bacterial infections represent a serious threat in modern medicine. In particular, biofilm treatment in clinical settings is challenging, as biofilms are very resistant to conventional antibiotic therapy and may spread infecting other tissues. To address this problem, biosensing technologies are emerging as a powerful solution to detect and identify bacterial pathogens at the very early stages of the infection, thus allowing rapid and effective treatments before biofilms are formed. Biosensors typically consist of two main parts, a biorecognition moiety that interacts with the target (i.e., bacteria) and a platform that transduces such interaction into a measurable signal. This review will focus on the development of impedimetric biosensors using antimicrobial peptides (AMPs) as biorecognition elements. AMPs belong to the innate immune system of living organisms and are very effective in interacting with bacterial membranes. They offer unique advantages compared to other classical bioreceptor molecules such as enzymes or antibodies. Moreover, impedance-based sensors allow the development of label-free, rapid, sensitive, specific and cost-effective sensing platforms. In summary, AMPs and impedimetric transducers combine excellent properties to produce robust biosensors for the early detection of bacterial infections. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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Open AccessReview Antibacterial Peptides in Dermatology–Strategies for Evaluation of Allergic Potential
Molecules 2018, 23(2), 414; https://doi.org/10.3390/molecules23020414
Received: 20 January 2018 / Revised: 9 February 2018 / Accepted: 13 February 2018 / Published: 14 February 2018
Cited by 1 | PDF Full-text (718 KB) | HTML Full-text | XML Full-text
Abstract
During recent decades, the market for peptide-based drugs, including antimicrobial peptides, has vastly extended and evolved. These drugs can be useful in treatment of various types of disorders, e.g., cancer, autoimmune diseases, infections, and non-healing wounds. Although peptides are less immunogenic than other
[...] Read more.
During recent decades, the market for peptide-based drugs, including antimicrobial peptides, has vastly extended and evolved. These drugs can be useful in treatment of various types of disorders, e.g., cancer, autoimmune diseases, infections, and non-healing wounds. Although peptides are less immunogenic than other biologic therapeutics, they can still induce immune responses and cause allergies. It is important to evaluate the immunogenic and allergic potential of peptides before they are forwarded to the expensive stages of clinical trials. The process of the evaluation of immunogenicity and cytotoxicity is complicated, as in vitro models and bioinformatics tools cannot fully simulate situations in the clinic. Nevertheless, several potentially promising tests for the preclinical evaluation of peptide drugs have been implemented (e.g., cytotoxicity assays, the basophil activation test, and lymphocyte activation assays). In this review, we focus on strategies for evaluation of the allergic potential of peptide-based therapeutics. Full article
(This article belongs to the Special Issue Antimicrobial Peptides and Peptidomimetics)
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