Antimicrobial Peptides (AMPs) are one of the most common components of the innate immune system that protect multicellular organisms against microbial invasion. The vast majority of AMPs are isolated from the frog skin. Anuran (frogs and toads) skin contains abundant AMPs that can be developed therapeutically. Such peptides are a unique but diverse group of molecules. In general, more than 50% of the amino acid residues form the hydrophobic part of the molecule. Normally, there are no conserved structural motifs responsible for activity, although the vast majority of the AMPs are cationic due to the presence of multiple lysine residues; this cationicity has a close relationship with antibacterial activity. Notably, recent evidence suggests that synthesis of AMPs in frog skin may confer an advantage on a particular species, although they are not essential for survival. Frog skin AMPs exert potent activity against antibiotic-resistant bacteria, protozoa, yeasts, and fungi by permeating and destroying the plasma membrane and inactivating intracellular targets. Importantly, since they do not bind to a specific receptor, AMPs are less likely to induce resistance mechanisms. Currently, the best known amphibian AMPs are esculentins, brevinins, ranacyclins, ranatuerins, nigrocin-2, magainins, dermaseptins, bombinins, temporins, and japonicins-1 and -2, and palustrin-2. This review focuses on these frog skin AMPs and the mechanisms underlying their antimicrobial activity. We hope that this review will provide further information that will facilitate further study of AMPs and cast new light on novel and safer microbicides.

• Klíčová slova
• Antimicrobial peptides (AMPs), amphibian defense peptides, antibacterial, brevinins, esculentins, ranacyclins, ranatuerins.,
• MeSH
• antiinfekční látky chemie   farmakologie   MeSH
• Bacteria účinky léků   MeSH
• Eukaryota účinky léků   MeSH
• houby účinky léků   MeSH
• kationické antimikrobiální peptidy chemie   farmakologie   MeSH
• kůže chemie   MeSH
• lidé MeSH
• žáby MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• antiinfekční látky MeSH
• kationické antimikrobiální peptidy MeSH

Plant antimicrobial peptides (AMPs) are a component of barrier defense system of plants. They have been isolated from roots, seeds, flowers, stems, and leaves of a wide variety of species and have activities towards phytopathogens, as well as against bacteria pathogenic to humans. Thus, plant AMPs are considered as promising antibiotic compounds with important biotechnological applications. Plant AMPs are grouped into several families and share general features such as positive charge, the presence of disulfide bonds (which stabilize the structure), and the mechanism of action targeting outer membrane structures.

• MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• antifungální látky chemie   farmakologie   MeSH
• antiinfekční látky chemie   klasifikace   farmakologie   MeSH
• biotechnologie MeSH
• fyziologie rostlin * MeSH
• kationické antimikrobiální peptidy chemie   klasifikace   farmakologie   MeSH
• penetrační peptidy chemie   farmakologie   MeSH
• rostliny chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antibakteriální látky MeSH
• antifungální látky MeSH
• antiinfekční látky MeSH
• kationické antimikrobiální peptidy MeSH
• penetrační peptidy MeSH

Antimicrobial peptides are currently considered as promising antiviral compounds. Current assays to evaluate the effectivity of peptides against enveloped viruses based on liposomes or hemolysis are encumbered by the artificial nature of liposomes or distinctive membrane composition of used erythrocytes. We propose a novel assay system based on enzymatic Ebola virus-like particles containing sensitive luciferase reporter. The assay was validated with several cationic and anionic peptides and compared with lentivirus inactivation and hemolytic assays. The assay is sensitive and easy to perform in standard biosafety level laboratory with potential for high-throughput screens. The use of virus-like particles in the assay provides a system as closely related to the native viruses as possible eliminating some issues associated with other more artificial set ups. We have identified CAM-W (KWKLWKKIEKWGQGIGAVLKWLTTWL) as a peptide with the greatest antiviral activity against infectious lentiviral vectors and filoviral virus-like particles.

• Klíčová slova
• Antimicrobial peptides, Cytotoxic peptides, Ebola, Hemolytic activity, Lentivirus, Marburg, Nanoluciferase, Virolytic activity, Virus-like particles,
• MeSH
• anionty MeSH
• antivirové látky farmakologie   MeSH
• hemoragická horečka Ebola prevence a kontrola   virologie   MeSH
• kationické antimikrobiální peptidy farmakologie   MeSH
• Lentivirus účinky léků   genetika   MeSH
• lidé MeSH
• liposomy chemie   MeSH
• peptidy farmakologie   MeSH
• virus Ebola účinky léků   patogenita   MeSH
• VLP vakcíny MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• anionty MeSH
• antivirové látky MeSH
• kationické antimikrobiální peptidy MeSH
• liposomy MeSH
• peptidy MeSH
• VLP vakcíny MeSH

Antimicrobial peptides are an important component of many organisms' innate immune system, with a good inhibitory or killing effect against the invading pathogens. As a type of biological polypeptide with natural immune activities, antimicrobial peptides have a broad spectrum of antibacterial, antiviral, and antitumor activities. Nevertheless, these peptides cause no harm to the organisms themselves. Compared with traditional antibiotics, antimicrobial peptides have the advantage of not producing drug resistance and have a unique antibacterial mechanism, which has attracted widespread attention. In this study, marine invertebrates were classified into arthropods, annelids, mollusks, cnidarians, and tunicata. We then analyzed the types, sources and antimicrobial activities of the antimicrobial peptides in each group. We also reviewed the immune mechanism from three aspects: membrane-targeted direct killing effects, non-membrane targeting effects and immunomodulatory effects. Finally, we discussed their applications and the existing problems facing antimicrobial peptides in actual production. The results are expected to provide theoretical support for future research and applications of antimicrobial peptides in marine invertebrates.

• Klíčová slova
• activity, antimicrobial peptides, marine, marine invertebrate, mechanism,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Antimicrobial peptides have long been considered as promising compounds against drug-resistant pathogens. In this work, we studied the secondary structure of antimicrobial peptides melectin and antapin using electronic (ECD) and vibrational circular dichroism (VCD) spectroscopies that are sensitive to peptide secondary structures. The results from quantitative ECD spectral evaluation by Dichroweb and CDNN program and from the qualitative evaluation of the VCD spectra were compared. The antimicrobial activity of the selected peptides depends on their ability to adopt an amphipathic α-helical conformation on the surface of the bacterial membrane. Hence, solutions of different zwitterionic and negatively charged liposomes and micelles were used to mimic the eukaryotic and bacterial biological membranes. The results show a significant content of α-helical conformation in the solutions of negatively charged liposomes mimicking the bacterial membrane, thus correlating with the antimicrobial activity of the studied peptides. On the other hand in the solutions of zwitterionic liposomes used as models of the eukaryotic membranes, the fraction of α-helical conformation was lower, which corresponds with their moderate hemolytic activity.

• Klíčová slova
• Antimicrobial peptides, Circular dichroism, Conformation, Infrared spectroscopy, Liposomes, Model membranes,
• MeSH
• buněčná membrána chemie   MeSH
• cirkulární dichroismus MeSH
• dodecylsíran sodný chemie   MeSH
• hemolýza účinky léků   MeSH
• kationické antimikrobiální peptidy chemie   MeSH
• konformace proteinů MeSH
• lipidové dvojvrstvy chemie   MeSH
• liposomy MeSH
• micely MeSH
• mikrobiální testy citlivosti MeSH
• oxid deuteria chemie   MeSH
• roztoky MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antapin MeSH Prohlížeč
• dodecylsíran sodný MeSH
• kationické antimikrobiální peptidy MeSH
• lipidové dvojvrstvy MeSH
• liposomy MeSH
• melectin MeSH Prohlížeč
• micely MeSH
• oxid deuteria MeSH
• roztoky MeSH

Probiotics modulate production of both cytokine and antimicrobial peptides. This effect can be regarded as a part of complex interplay between them and the host.

• MeSH
• Bifidobacterium imunologie   MeSH
• cytokiny metabolismus   MeSH
• kationické antimikrobiální peptidy metabolismus   MeSH
• Lactobacillus imunologie   MeSH
• lidé MeSH
• probiotika farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• cytokiny MeSH
• kationické antimikrobiální peptidy MeSH

Four new peptides of the mastoparan family, characterized recently in the venom of three neotropical social wasps collected in the Dominican Republic, Polistes major major, Polistes dorsalis dorsalis and Mischocyttarus phthisicus were synthesized and tested for antimicrobial potency against Bacillus subtilis, Staphylococcus aureus, Escherichia coli (E.c.) and Pseudomonas aeruginosa, and for hemolytic and mast cells degranulation activities. As these peptides possess strong antimicrobial activity (minimal inhibitory concentration (MIC) values against Bacillus subtillis and E.c. in the range of 5-40 microM), we prepared 40 of their analogs to correlate biological activities, especially antimicrobial, with the net positive charge, hydrophobicity, amphipathicity, peptide length, amino acid substitutions at different positions of the peptide chain, N-terminal acylation and C-terminal deamidation. Circular dichroism spectra of the peptides measured in the presence of trifluoroethanol or SDS showed that the peptides might adopt alpha-helical conformation in such anisotropic environments.

• MeSH
• antibakteriální látky chemická syntéza   chemie   farmakologie   MeSH
• Bacillus subtilis účinky léků   MeSH
• degranulace buněk MeSH
• erytrocyty účinky léků   MeSH
• Escherichia coli účinky léků   MeSH
• hemolýza účinky léků   fyziologie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• inhibiční koncentrace 50 MeSH
• kationické antimikrobiální peptidy chemická syntéza   chemie   farmakologie   MeSH
• krysa rodu Rattus MeSH
• mastocyty účinky léků   fyziologie   MeSH
• mikrobiální testy citlivosti MeSH
• molekulární sekvence - údaje MeSH
• peptidy chemická syntéza   chemie   genetika   izolace a purifikace   farmakologie   MeSH
• Pseudomonas aeruginosa účinky léků   MeSH
• sekvence aminokyselin MeSH
• sršňovití chemie   MeSH
• Staphylococcus aureus účinky léků   MeSH
• substituce aminokyselin MeSH
• vosí jedy chemie   genetika   farmakologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky MeSH
• kationické antimikrobiální peptidy MeSH
• peptidy MeSH
• vosí jedy MeSH

Capillary electrophoresis (CE) was employed for the determination of thermodynamic acidity constants (pKa ) and actual ionic mobilities of polycationic antimicrobial peptides (AMPs). The effective electrophoretic mobilities of AMPs were measured by CE in a series of the background electrolytes within a wide pH range (2.00-12.25), at constant ionic strength (25 mM) and ambient temperature, using polybrene coated fused silica capillaries to suppress sorption of cationic AMPs to the capillary wall. Eventually, Haarhoff-Van der Linde peak fitting function was used for the determination of correct migration times of some AMPs peaks that were distorted by electromigration dispersion. The measured effective mobilities were corrected to 25°C. Mixed acidity constants, pKa,i mix , and actual ionic mobilities, mi , of AMPs were determined by the nonlinear regression analysis of pH dependence of their effective mobilities. The pKa,i mix values were recalculated to thermodynamic pKa s using the Debye-Hückel theory. Thermodynamic pKa of imidazolium group of histidine residues was found to be in the range 3.72-4.98, pKa of α-NH3+ group was in the range 6.14-6.93, and pKa of ε-NH3+ group of lysine spanned the interval 7.26-9.84, depending on the particular amino acid sequence of the AMPs. Actual ionic mobilities of AMPs with positive charges from one to six elementary units achieved values (9.8 - 36.5) × 10-9 m2 V-1 s-1 .

• Klíčová slova
• Acid dissociation constant, Antimicrobial peptides, Charge, Mobility, Pka,
• MeSH
• aminokyseliny chemie   MeSH
• elektroforéza kapilární metody   MeSH
• kationické antimikrobiální peptidy analýza   chemie   MeSH
• koncentrace vodíkových iontů MeSH
• nelineární dynamika MeSH
• osmolární koncentrace MeSH
• termodynamika MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aminokyseliny MeSH
• kationické antimikrobiální peptidy MeSH

An infecting and propagating parasite relies on its innate defense system to evade the host's immune response and to survive challenges from commensal bacteria. More so for the nematode Anisakis, a marine parasite that during its life cycle encounters both vertebrate and invertebrate hosts and their highly diverse microbiotas. Although much is still unknown about how the nematode mitigates the effects of these microbiota, its antimicrobial peptides likely play an important role in its survival. We identified anisaxins, the first cecropin-like helical antimicrobial peptides originating from a marine parasite, by mining available genomic and transcriptomic data for Anisakis spp. These peptides are potent bactericidal agents in vitro, selectively active against Gram-negative bacteria, including multi-drug resistant strains, at sub-micromolar concentrations. Their interaction with bacterial membranes was confirmed by solid state NMR (ssNMR) and is highly dependent on the peptide concentration as well as peptide to lipid ratio, as evidenced by molecular dynamics (MD) simulations. MD results indicated that an initial step in the membranolytic mode of action involves membrane bulging and lipid extraction; a novel mechanism which may underline the peptides' potency. Subsequent steps include membrane permeabilization leading to leakage of molecules and eventually cell death, but without visible macroscopic damage, as shown by atomic force microscopy and flow cytometry. This membranolytic antibacterial activity does not translate to cytotoxicity towards human peripheral blood mononuclear cells (HPBMCs), which was minimal at well above bactericidal concentrations, making anisaxins promising candidates for further drug development. STATEMENT OF SIGNIFICANCE: Witnessing the rapid spread of antibiotic resistance resulting in millions of infected and dozens of thousands dying worldwide every year, we identified anisaxins, antimicrobial peptides (AMPs) from marine parasites, Anisakis spp., with potent bactericidal activity and selectivity towards multi-drug resistant Gram-negative bacteria. Anisaxins are membrane-active peptides, whose activity, very sensitive to local peptide concentrations, involves membrane bulging and lipid extraction, leading to membrane permeabilization and bacterial cell death. At the same time, their toxicity towards host cells is negligible, which is often not the case for membrane-active AMPs, therefore making them suitable drug candidates. Membrane bulging and lipid extraction are novel concepts that broaden our understanding of peptide interactions with bacterial functional structures, essential for future design of such biomaterials.

• Klíčová slova
• Anisakis, Lipid extraction, Molecular leakage, Multi-drug resistant bacteria, Parasites, α-helical antimicrobial peptides,
• MeSH
• antibakteriální látky farmakologie   MeSH
• antimikrobiální peptidy MeSH
• Bacteria MeSH
• kationické antimikrobiální peptidy chemie   farmakologie   MeSH
• leukocyty mononukleární MeSH
• lidé MeSH
• lipidy farmakologie   MeSH
• mikrobiální testy citlivosti MeSH
• paraziti * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky MeSH
• antimikrobiální peptidy MeSH
• kationické antimikrobiální peptidy MeSH
• lipidy MeSH

We have investigated structural changes of peptides related to antimicrobial peptide Halictine-1 (HAL-1) induced by interaction with various membrane-mimicking models with the aim to identify a mechanism of the peptide mode of action and to find a correlation between changes of primary/secondary structure and biological activity. Modifications in the HAL-1 amino acid sequence at particular positions, causing an increase of amphipathicity (Arg/Lys exchange), restricted mobility (insertion of Pro) and consequent changes in antimicrobial and hemolytic activity, led to different behavior towards model membranes. Secondary structure changes induced by peptide-membrane interaction were studied by circular dichroism, infrared spectroscopy, and fluorescence spectroscopy. The experimental results were complemented by molecular dynamics calculations. An α-helical structure has been found to be necessary but not completely sufficient for the HAL-1 peptides antimicrobial action. The role of alternative conformations (such as β-sheet, PPII or 310-helix) also seems to be important. A mechanism of the peptide mode of action probably involves formation of peptide assemblies (possibly membrane pores), which disrupt bacterial membrane and, consequently, allow membrane penetration.

• Klíčová slova
• antibacterial peptides, circular dichroism, fluorescence, halictine, infrared spectroscopy,
• MeSH
• antibakteriální látky chemie   metabolismus   MeSH
• fosfatidylcholiny chemie   MeSH
• fosfatidylglyceroly chemie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• kationické antimikrobiální peptidy chemie   metabolismus   MeSH
• kinetika MeSH
• konformace proteinů, alfa-helix MeSH
• konformace proteinů, beta-řetězec MeSH
• lipidové dvojvrstvy chemie   MeSH
• permeabilita MeSH
• sekvence aminokyselin MeSH
• simulace molekulární dynamiky MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• fosfatidylcholiny MeSH
• fosfatidylglyceroly MeSH
• kationické antimikrobiální peptidy MeSH
• lipidové dvojvrstvy MeSH