TY - JOUR. T1 - Improvement of outer membrane-permeabilizing and lipopolysaccharide- binding activities of an antimicrobial cationic peptide by C-terminal modification. AU - Piers, K. L.. AU - Brown, M. H.. AU - Hancock, Robert. PY - 1994/1/1. Y1 - 1994/1/1. N2 - Antimicrobial cationic peptides have been discovered in many different organisms and often possess a broad range of activity. In this study, we investigated the mechanisms of actions of melittin and two synthetic peptides, CEME (a cecropin-melittin hybrid) and CEMA, against gram-negative bacteria. CEMA was produced by recombinant DNA procedures and is an analog of CEME with a modified C terminus resulting in two additional positive charges. All three peptides showed good antimicrobial activity against four different gram-negative bacteria, but only CEMA was able to somewhat augment the activity of some conventional antibiotics in synergy studies. Studies using the bacteria Pseudomonas aeruginosa and Enterobacter cloacae showed that the ...
114118PRTArtificial SequenceSynthetic antimicrobial polypeptide 1Lys Asn Leu Arg Arg Ile Ile Arg Lys Gly Ile His Ile Ile Lys Lys1 5 10 15Tyr Gly218PRTArtificial SequenceSynthetic antimicrobial polypeptide 2Lys Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa1 5 10 15Xaa Xaa318PRTArtificial SequenceSynthetic antimicrobial polypeptide 3Lys Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa1 5 10 15Xaa Xaa418PRTArtificial SequenceSynthetic antimicrobial polypeptide 4Lys Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Arg Xaa Xaa Xaa Xaa1 5 10 15Xaa Xaa518PRTArtificial SequenceSynthetic antimicrobial polypeptide 5Lys Gly Leu Arg Arg Ile Ile Arg Lys Gly Ile His Ile Ile Lys Lys1 5 10 15Tyr Gly618PRTArtificial SequenceSynthetic antimicrobial polypeptide 6Lys Gly Leu Arg Arg Ile Ile Arg Trp Gly Ile His Ile Ile Lys Lys1 5 10 15Tyr Gly718PRTArtificial SequenceSynthetic antimicrobial polypeptide 7Lys Ile Leu Arg Arg Ile Ile Arg Lys Gly Ile His Ile Ile Lys Lys1 5 10 15Tyr Gly818PRTArtificial ...
This study conclusively demonstrates that endotoxin-induced inflammatory gene responses and cytokine secretion in monocytes were suppressed by low, physiological concentrations of LL-37, implicating LL-37 in the regulation and control of proinflammatory responses associated with pathogenic assault and, by extension, with homeostatic levels of TLR agonists secreted by commensals. This report further demonstrates that LL-37 can suppress LPS-induced NF-κB translocation and exert an anti-inflammatory effect that is not restricted to endotoxin-induced inflammation. In the human THP-1 monocytic cell line as well as in human PBMC, LL-37 suppressed proinflammatory cytokine production induced by LPS as well as other agonists of TLR2 (LTA, Pam3CSK4) and in part TLR9 (CpG), but selectively enhanced responses to the proinflammatory cytokines IL-1β and TNF-α. Selective enhancement of responses is consistent with the known complex interaction of LL-37 with cells (20, 38), including the induction of a ...
PURPOSE Antimicrobial peptides (AMPs) are cationic host defense peptides with microbicidal and cell-signaling properties. They show promise as potential therapeutic agents. In the present study, a beta-defensin AMP gene was isolated from the ocular surface for the first time, and its expression was characterized in the presence of ocular inflammation and/or infection. METHODS Total RNA was obtained from impression cytology samples of the conjunctiva and cornea of normal patients and of those with bacterial, viral, acanthamoeba, or dry eye disease. The expression of the beta-defensin AMP DEFB-109 was determined by using reverse transcription-polymerase chain reaction (RT-PCR). Relative quantification of the gene in the various groups was performed by means of real-time PCR. RESULTS DEFB-109 was constitutively expressed in all samples. The gene showed significantly decreased expression in the presence of all types of inflammation/infection. Reduced expression featured most prominently in acanthamoeba
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Disclosed are novel bactericidal/permeability-increasing (BPI) protein products wherein cysteine residue number 132 or 135 is replaced by another amino acid residue, preferably an alanine or serine residue and/or wherein the leucine residue at position 193 is the carboxy terminal residue. Also disclosed are DNA sequences encoding methods for the production of the same in appropriate host cells, and stable homogeneous pharmaceutical compositions containing the analogs suitable for use treatment of gram negative bacterial infection and its sequelae.
Barlow, P. G., Li, Y., Wilkinson, T. S., Bowdish, D. M. E., Lau, Y. E., Cosseau, C., …Davidson, D. J. (2005). The human cationic host defense peptide LL-37 mediates contrasting effects on apoptotic pathways in different primary cells of the innate immune system. Journal of Leukocyte Biology. 80, 509-520. doi:10.1189/jlb.1005560. ISSN 0741-5400. ...
Barlow, P. G., Li, Y., Wilkinson, T. S., Bowdish, D. M. E., Lau, Y. E., Cosseau, C., …Davidson, D. J. (2005). The human cationic host defense peptide LL-37 mediates contrasting effects on apoptotic pathways in different primary cells of the innate immune system. Journal of Leukocyte Biology. 80, 509-520. doi:10.1189/jlb.1005560. ISSN 0741-5400. ...
Background: Antimicrobial peptides (AMPs) are synthesized and secreted by immune and epithelial cells that are constantly exposed to environmental microbes. AMPs are essential for barrier defense and deficiencies lead to increased susceptibility to infection. In addition to their ability to disrupt the integrity of bacterial, viral and fungal membranes, AMPs bind lipopolysaccharides, act as chemoattractants for immune cells and bind to cellular receptors and modulate the expression of cytokines and chemokines. These additional biological activities may explain the role of AMPs in inflammatory diseases and cancer. Modulating the endogenous expression of AMPs offers potential therapeutic treatments for infection and disease. Methods: The present review examines published data from both in vitro and in vivo studies reporting effects of nutrients and byproducts of microbial metabolism on the expression of antimicrobial peptide genes in order to highlight an emerging appreciation for the role of ...
Host defense peptides (HDPs) are an important first line of defense with antimicrobial and immunomoduatory properties. Because they act on the microbial membranes or host immune cells, HDPs pose a low risk of triggering microbial resistance and therefore, are being actively investigated as a novel class of antimicrobials and vaccine adjuvants. Cathelicidins and β-defensins are two major families of HDPs in avian species. More than a dozen HDPs exist in birds, with the genes in each HDP family clustered in a single chromosomal segment, apparently as a result of gene duplication and diversification. In contrast to their mammalian counterparts that adopt various spatial conformations, mature avian cathelicidins are mostly α-helical. Avian β-defensins, on the other hand, adopt triple-stranded β-sheet structures similar to their mammalian relatives. Besides classical β-defensins, a group of avian-specific β-defensin-related peptides, namely ovodefensins, exist with a different six-cysteine motif. Like
1. SteinerH, HultmarkD, EngstromA, BennichH, BomanHG (1981) Sequence and specificity of two antibacterial proteins involved in insect immunity. Nature 292: 246-248.. 2. ZasloffM (1987) Magainins, a class of antimicrobial peptides from Xenopus skin: isolation, characterization of two active forms, and partial cDNA sequence of a precursor. Proc Natl Acad Sci USA 84: 5449-5453.. 3. GanzT, SelstedME, LehrerRI (1990) Defensins. Eur J Haematol 44: 1-8.. 4. BrogdenKA (2005) Antimicrobial peptides: pore formers or metabolic inhibitors in bacteria? Nature Rev Microbiol 3: 238-250.. 5. HancockREW, SahlH-G (2006) Antimicrobial and host-defense peptides as new anti-infective therapeutic strategies. Nature Biotech 24: 1551-1557.. 6. PeschelA, SahlH-G (2006) The co-evolution of host cationic antimicrobial peptides and microbial resistance. Nature Rev Microbiol 4: 529-536.. 7. HaleJDF, HancockREW (2007) Alternative mechanisms of action of cationic antimicrobial peptides on bacteria. Expert Rev Anti Infect Ther ...
National Pirogov Memorial Medical University, Vinnytsya, Ukraine Purpose - to determine the activity of antimicrobial peptides, such as cathelicidin LL-37 and 25-hydroxycholecalciferol in children with asthma. Materials and methods. We have comprehensively examined 200 children with asthma aged 6 to 17 years. The contents of 25(OH)D3 and cathelicidin LL-37 in serum were determined by ELISA according to the instructions of the manufacturer. Results. The examination revealed that the total content of 25(OH)D3 in the serum of children with asthma differs from the values of healthy children and characterized by a significant decrease of its level (p,0.01). Concentration of cathelicidin LL-37 in patients with asthma was significantly higher (p,0.001), than in the group of healthy children. The positive correlation between the cathelicidin LL-37, interleukin 1 (rxy=0.398 (p=0.02)) and interleukin 6 (rxy=0.178 (p=0.034)) in children with asthma was determined. The concentration of cathelicidin LL-37 in ...
There has been increasing concern regarding the emergence of multi-drug resistant pathogens. The resistance develops when pathogens, especially bacteria, are frequently exposed to conventional antibiotics, as they are heavily used in both human and livestock. This is due to the high target specificity of conventional antibiotics, which places pathogens in high selective pressures and eventually results in drug resistant by mutations. To address this issue, global actions and cooperation are needed. At the same time, new technologies and strategies need to be developed. Host defense peptides (HDPs) are widely found in the innate immune system. They show both direct antimicrobial properties and immunomodulatory activities. The multifaceted functions of HPDs make them less likely to promote antimicrobial resistance. Thus, they are promising as new therapeutics to treat multi-drug resistant infections. In fact, several drug candidates derived from HDPs have entered the clinical trial, but none of them got
Host defense peptides (HDPs) are positively-charged and amphipathic components of the innate immune system that have demonstrated great potential to become the next generation of broad spectrum therapeutic agents effective against a vast array of pathogens and tumor. As such, many approaches have been taken to improve the therapeutic efficacy of HDPs. Amongst these methods, the incorporation of d-amino acids (d-AA) is an approach that has demonstrated consistent success in improving HDPs. Although, virtually all HDP review articles briefly mentioned about the role of d-AA, however it is rather surprising that no systematic review specifically dedicated to this topic exists. Given the impact that d-AA incorporation has on HDPs, this review aims to fill that void with a systematic discussion of the impact of d-AA on HDPs.. ...
Donald J Davidsons lab studies the role of cationic host defence peptides (antimicrobial peptides) as modulators of cell death, inflammation and immunity in infectious and inflammatory lung diseases, and innate immune signalling.
This comprehensive database for antimicrobial peptides is manually curated based on a set of data-collection criteria. There are 139 human host defense peptides, 305 from mammals annotated, 1087 active peptides from amphibians (1018 from frogs), 134 fish peptides, 45 reptile peptides, 42 from birds, 559 from arthropods, [310 from insects, 69 from crustaceans, 7 from myriapods, 171 from chelicerata, (43 from spiders, 88 from scorpions)], 45 from molluscs, 6 AMPs from protozoa, and more. Of the 428 unique NMR/X-ray diffracted 3D structures annotated for host defense peptides in the APD, 301 with coordinates deposited in the Protein Data Bank (PDB) can be directly rotated, zoomed, and viewed. Top left: Amphibian α-helical magainin II; Top right: bovine β-sheet lactoferricin; Bottom left: plant αβ-PsD1; Bottom right: bovine non-αβ indolicidin. This original database consists of a pipeline of search functions for innate immune peptides. You can search for peptide information using APD ID, ...
This comprehensive database for antimicrobial peptides is manually curated based on a set of data-collection criteria. There are 141 human host defense peptides, 328 from mammals annotated, 1117 active peptides from amphibians (1037 from frogs and 76 from toads), 136 fish peptides, 45 reptile peptides, 43 from birds, 577 from arthropods, [323 from insects, 71 from crustaceans, 8 from myriapods, 175 from chelicerata, (43 from spiders, 88 from scorpions)], 47 from molluscs, 6 AMPs from protozoa, and more. Of the 443 unique NMR/X-ray diffracted 3D structures annotated for host defense peptides in the APD, 316 with coordinates deposited in the Protein Data Bank (PDB) can be directly rotated, zoomed, and viewed. Top left: Amphibian α-helical magainin II; Top right: bovine β-sheet lactoferricin; Bottom left: plant αβ-PsD1; Bottom right: bovine non-αβ indolicidin. This original database consists of a pipeline of search functions for innate immune peptides. You can search for peptide information ...
Zhu SY,Gao B. Positive Selection in Cathelicidin Host Defense Peptides: Adaptation to Exogenous Pathogens or Endogenous Receptors?[J]. Heredity,2017,118(5):453-465 ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Host defence peptides (HDPs) are polypeptide sequences found ubiquitously in nature that have garnered significant attention as alternatives to antibiotics. Originally appreciated for their direct antibacterial effect, recent work has revealed that many HDPs possess antibiofilm activity, anticancer activity and/or the ability to modulate the immune response of the host.
Eduardo R. Cobo Scientific laboratory (University of Calgary) studying innate immune functions of epithelial cells and leukocytes contributed by host defense peptides.
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Indolicidin Targets Duplex DNA: Structural and Mechanistic Insight through a Combination of Spectroscopy and Microscopy.. Ghosh A, Kar RK, Jana J, Saha A, Jana B, Krishnamoorthy J, Kumar D, Ghosh S, Chatterjee S, Bhunia A, ChemMedChem, 2014, 9, 2052-8.. Indolicidin (IR13), a 13-residue antimicrobial peptide from the cathelicidin family, is known to exhibit a broad spectrum of antimicrobial activity against various microorganisms. This peptide inhibits bacterial DNA synthesis resulting in cell filamentation. However, the precise mechanism remains unclear and requires further investigation. The central PWWP motif of IR13 provides a unique structural element that can wrap around, and thus stabilize, duplex B-type DNA structures. Replacements of the central Trp-Trp pair with Ala-Ala, His-His, or Phe-Phe residues in the PxxP motif significantly affects the ability of the peptide to stabilize duplex DNA. Results of microscopy studies in conjunction with spectroscopic data confirm that the DNA duplex ...
Antimicrobial peptides, Cationic antimicrobial peptides, Cathelicidins, Defensins, Host defence peptides, Microbicidal cationic proteins. Authoritative facts from DermNet New Zealand.
Bactericidal/permeability-increasing protein (BPI), a cationic protein isolated from human neutrophils, binds lipopolysaccharide (LPS), kills gram-negative bacteria, and neutralizes many of the effects of LPS in vitro and in vivo. We hypothesized that a recombinant 23-kDa NH2-terminal fragment of BPI (BPI23) would reduce acute lung injury in endotoxemic pigs. At -18 h, pigs received an intravenous priming dose of LPS (20 micrograms/kg). Anesthetized ventilated swine were randomized to receive 1) no further treatment (n = 4); 2) LPS (250 micrograms/kg over 50 min) and BPI23 (3-mg/kg bolus and 3 mg/kg over 60 min) (n = 6); or 3) LPS and thaumatin, a cationic protein devoid of LPS neutralizing activity that has a molecular mass and isoelectric point that are similar to that of BPI23 (n = 7). BPI23 treatment significantly ameliorated LPS-induced hypoxemia, functional upregulation of opsonin receptors on circulating phagocytes, and alveolitis but had no effect on the elaboration of tumor necrosis ...
CUONG, Ng.V. et al. Polymorphisms of candidate genes associated with meat quality and disease resistance in indigenous and exotic pig breeds of Vietnam. S. Afr. j. anim. sci. [online]. 2012, vol.42, n.3, pp.221-231. ISSN 2221-4062.. The objectives of this study were to analyse genotype distribution and sequence variations of candidate genes putatively associated with meat quality and disease resistance in exotic and indigenous Vietnamese pig breeds. For this purpose, 340 pigs from four indigenous and two exotic breeds were included in the analysis of the polymorphisms of the heart fatty-acid-binding protein (H-FABP), alpha 1 fucosyltransferase (FUT1), and bactericidal/permeability-increasing protein (BPI) genes by the sequencing and PCR-RFLP methods. For H-FABP, 17 single nucleotide polymorphisms (SNPs) were detected in indigenous pig breeds by direct sequencing of a fragment at intron 2 of the H-FABP gene. The mutation T1556C created a new restriction site for the enzyme MspI, which gave rise ...
This application is in response to PA-09-164 (NIH Exploratory Developmental Research Grant Program). Given the high rate of hospital-acquired infection in criti...
Sandrine Ménard, Valentina Förster, Michael Lotz, Dominique Gütle, Claudia U. Duerr, Richard L. Gallo, Birgitta Henriques-Normark, Katrin Pütsep, Mats Andersson, Erik O. Glocker, Mathias W. Hornef ...
TY - CONF. T1 - Versatile interactions of the antimicrobial peptide novispirin with detergents and lipids. AU - Wimmer, Reinhard. AU - Andersen, Kell. AU - Davidsen, Mads. AU - Mølgaard, Søren. AU - Nesgaard, Lise. AU - Kristensen, Hans Henrik. AU - Vad, Brian. AU - Otzen, Daniel. PY - 2006. Y1 - 2006. M3 - Paper without publisher/journal. Y2 - 20 August 2006 through 26 August 2006. ER - ...
DUGi: Viewing Item from repository Recercat: The presence of the antimicrobial peptide (AMP) biosynthetic genes srfAA (surfactin), bacA (bacylisin), fenD (fengycin), bmyB (bacyllomicin), spaS (subtilin), and ituC (iturin) was examined in 184 isolates of Bacillus spp. obtained from plant environments (aerial, rhizosphere, soil) in the Mediterranean land area of Spain. Most strains had between two and four AMP genes whereas strains with five genes were seldom detected and none of the strains had six genes. The most frequent AMP gene markers were srfAA, bacA, bmyB, and fenD, and the most frequent genotypes srfAA-bacA-bmyB and srfAAbacA-bmyB-fenD. The dominance of these particular genes in Bacillus strains associated with plants reinforces the competitive role of surfactin, bacyllomicin, fengycin, and bacilysin in the fitness of strains in natural environments. The use of these AMP gene markers may assist in the selection of putative biological control agents of plant pathogens
A method pioneered by MIT researchers might offer hope in finding a new generation of antibiotics, made of antimicrobial peptides. Antimicrobial peptides a
Antimicrobial peptides (AMPs) are found widely distributed through Nature, and participate in the innate host defense of each species. Fish are a great source of these peptides, as they express all of the major classes of AMPs, including defensins, cathelicidins, hepcidins, histone-derived peptides, and a fish-specific class of the cecropin family, called piscidins. As with other species, the fish peptides exhibit broad-spectrum antimicrobial activity, killing both fish and human pathogens. They are also immunomodulatory, and their genes are highly responsive to microbes and innate immuno-stimulatory molecules. Recent research has demonstrated that some of the unique properties of fish peptides, including their ability to act even in very high salt concentrations, make them good potential targets for development as therapeutic antimicrobials. Further, the stimulation of their gene expression by exogenous factors could be useful in preventing pathogenic microbes in aquaculture.
... Hepcidin (Liver Expressed Antimicrobial Peptide 1 or - Market research report and industry analysis - 10290125
abstract = {The production of antimicrobial peptides is an important aspect of host defense in multicellular organisms. In Drosophila, seven antimicrobial peptides with different spectra of activities are synthesized by the fat body during the immune response and secreted into the hemolymph. Using GFP reporter transgenes, we show here that all seven Drosophila antimicrobial peptides can be induced in surface epithelia in a tissue-specific manner. The imd gene plays a critical role in the activation of this local response to infection. In particular, drosomycin expression, which is regulated by the Toll pathway during the systemic response, is regulated by imd in the respiratory tract, thus demonstrating the existence of distinct regulatory mechanisms for local and systemic induction of antimicrobial peptide genes in Drosophila ...
Azurocidin, also known as cationic antimicrobial protein 37 kDa (CAP37) or heparin-binding protein (HBP) is an inactive homolog of serine proteinases residing in granulocytes. The ability to cleave peptide bond was lost due to replacement of two of the three residues from the conserved catalytic triad characteristic for serine proteinases. Azurocidin has a broad spectrum of antimicrobial activity, mainly against Gram-negative bacteria. It is also recognized as a multifunctional inflammatory mediator for its contracting effects on endothelial cells causing an increase of vascular permeability, capacity to bind endotoxin and ability to attract monocytes to inflammation sites ...
Protein & Peptide Letters publishes short papers in all important aspects of protein and peptide research, including structural studies, recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, drug design etc. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallisation, and preliminary structure determinations of biologically important proteins are acceptable. Purely theoretical papers are also acceptable provided they provide new insight into the principles of protein/peptide structure and function ...
TY - JOUR. T1 - Antimicrobial and cytolytic properties of the frog skin peptide, kassinatuerin-1 and its L- and D-lysine-substituted derivatives. AU - Conlon, J. Michael. AU - Abraham, Bency. AU - Galadari, Sehamuddin. AU - Knoop, Floyd C.. AU - Sonnevend, Agnes. AU - Pál, Tibor. PY - 2005/11/1. Y1 - 2005/11/1. N2 - Kassinatuerin-1, a 21-amino-acid C-terminally α-amidated peptide first isolated from the skin of the African frog Kassina senegalensis, adopts an amphipathic α-helical conformation in a membrane-mimetic solvent (50% trifluoroethanol) and shows broad-spectrum antimicrobial activity. However, its therapeutic potential is limited by its relatively high cytolytic activity against mammalian cells. The antimicrobial and cytolytic properties of a peptide are determined by an interaction between cationicity, hydrophobicity, α-helicity and amphipathicity. Replacement of the C-terminal α-amide group in kassinatuerin-1 by carboxylic acid decreased both cationicity and α-helicity, ...
சளிப்படலம் போன்ற ஒரு வண்ணமயமான திரவத்தினை சுரக்கும் தவளையானது (ஹைட்ரோஃபிளாஸ் பேஹுவிஸ்தாரா)( Hudrophylax bahuvistara) கேளராவில் கண்டுபிடிக்கப்பட்டு உள்ளது. தவளையின் தோலிலிருந்து வெளிப்படும் பிசுப்பிசுப்பான திரவத்தினை ஆய்வு செய்ததில் host defence peptides இருப்பது கண்டுபிடிக்கப்பட்டு உள்ளது. இந்த புதிய பெப்டைட்களுக்கு உருமின் என்று கேரளாவின் உறுமி வாளை நினைவுபடுத்தும் வகையில் பெயர்
The effectiveness of antimicrobial compounds can be easily screened, however their mechanism of action is much more difficult to determine. Many compounds act by compromising the mechanical integrity of the bacterial cell envelope, and our study introduces an AFM-based creep deformation technique to evaluate Interaction of nano-objects with lipid membranes
abstract = {The antimicrobial defence of Drosophila relies largely on the challenge-induced synthesis of an array of potent antimicrobial peptides by the fat body. The defence against Gram-positive bacteria and natural fungal infections is mediated by the Toll signalling pathway, whereas defence against Gram-negative bacteria is dependent on the Immune deficiency (IMD) pathway. Loss-of-function mutations in either pathway reduce the resistance to corresponding infections. The link between microbial infections and activation of these two pathways has remained elusive. The Toll pathway is activated by Gram-positive bacteria through a circulating Peptidoglycan recognition protein (PGRP-SA). PGRPs appear to be highly conserved from insects to mammals, and the Drosophila genome contains 13 members. Here we report a mutation in a gene coding for a putative transmembrane protein, PGRP-LC, which reduces survival to Gram-negative sepsis but has no effect on the response to Gram-positive bacteria or ...
abstract = {The antimicrobial defence of Drosophila relies largely on the challenge-induced synthesis of an array of potent antimicrobial peptides by the fat body. The defence against Gram-positive bacteria and natural fungal infections is mediated by the Toll signalling pathway, whereas defence against Gram-negative bacteria is dependent on the Immune deficiency (IMD) pathway. Loss-of-function mutations in either pathway reduce the resistance to corresponding infections. The link between microbial infections and activation of these two pathways has remained elusive. The Toll pathway is activated by Gram-positive bacteria through a circulating Peptidoglycan recognition protein (PGRP-SA). PGRPs appear to be highly conserved from insects to mammals, and the Drosophila genome contains 13 members. Here we report a mutation in a gene coding for a putative transmembrane protein, PGRP-LC, which reduces survival to Gram-negative sepsis but has no effect on the response to Gram-positive bacteria or ...
Over the last decade, antimicrobial peptides (AMPs) have emerged as a promising alternative for treatment of various infections. A large variety of AMPs have been identified and isolated from plants, animals and humans. The benefits of using AMPs are that they act by disrupting the bacteria membranes, a mechanism that is fast and non-specific. Therefore bacteria are not prone to develop high level resistance towards these compounds in the same extent as towards conventional antibiotics. AMPs are in general rather small (10-40 amino acid residues), cationic and amphiphilic compounds with a diversity in secondary structure which can be altered to different extent upon membrane interaction. Their structure has been developed for millenia during evolution and is today well preserved.. AMPs have been assessed, analyzed and modified in order to increase their function and efficiency for future drug delivery applications. In humans, AMPs are naturally present in high concentrations in tissues ...
Antimicrobial polypeptides has received significant attention because the challenge of serious multi-drug resistance of bacteria has been considered the most i...
Naturally present in the skin, a precursor in the biosynthesis of cholesterol and vitamin D3. Regulates skin cell differentiation and stimulates skin natural antimicrobial peptides. A 1% solution is also available ...
Multidrug antibiotic resistance is an increasingly serious public health problem worldwide. Thus, there is a significant and urgent need for the development of new classes of antibiotics that do not induce resistance. To develop such antimicrobial compounds, we must look toward agents with novel mechanisms of action. Membrane-permeabilizing antimicrobial peptides (AMPs) are good candidates because they act without high specificity toward a protein target, which reduces the likelihood of induced resistance. Understanding the mechanism of membrane permeabilization is crucial for the development of AMPs into useful antimicrobial agents. Various models, some phenomenological and others more quantitative or semimolecular, have been proposed to explain the action of AMPs. While these models explain many aspects of AMP action, none of the models captures all of the experimental observations, and significant questions remain unanswered. Here, we discuss the state of the field and pose some questions ...
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1F0F: Role of the hinge region and the tryptophan residue in the synthetic antimicrobial peptides, cecropin A(1-8)-magainin 2(1-12) and its analogues, on their antibiotic activities and structures.
Antimicrobial peptides (AMPs) are naturally occurring entities with potential as pharmaceutical candidates and/or food additives. They are present in many organisms including bacteria, insects, fish and mammals. While their antimicrobial activity is equipotent with many commercial antibiotics, current limitations are poor pharmacokinetics, stability and potential toxicology issues. Most elicit antimicrobial action via perturbation of bacterial membranes. Consequently, associated cytotoxicity in human cells is reflected by their capacity to lyse erythrocytes. However, more rigorous toxicological assessment of AMPs is required in order to predict potential failure at a later stage of development.Wedescribe a high-content analysis (HCA) screening protocol recently established for determination and prediction of safety in pharmaceutical drug discovery. HCA is a powerful, multi-parameter bioanalytical tool that amalgamates the actions of fluorescence microscopy with automated cell analysis software ...
Cationic antimicrobial peptides are becoming crucial for animal defense. The peptides can be induced through bacteria or other products. The peptide has a wide range of bacterial strains and this include antibiotic resistance. They have the potential to kill quickly and delay the selection of resistant mutants. These are synergistic to conventional antibiotics, lysozyme and other peptides. These will be able to kill the bacteria especially in test animals. The name given to it is bacterial infection and can be treated with antibiotics leading to the release of lipoteichoic acid and lipopolysaccharide (LPS) (bacterial products) leading to lethal sepsis. The peptides prevent cytokine induction with the help of bacterial products found tissue culture. It is said to block the beginning of sepsis in mouse models.. An array of experiments is conducted using macrophage cell and it has demonstrated a model peptide, it also blocks the reflection of the genes with induced LPS. The peptides initiates this ...
In recent years, the number of people suffering from cancer and multi-resistant infections has increased, such that both diseases are already seen as current and future major causes of death. Moreover, chronic infections are one of the main causes of cancer, due to the instability in the immune system that allows cancer cells to proliferate. Likewise, the physical debility associated with cancer or with anticancer therapy itself often paves the way for opportunistic infections. It is urgent to develop new therapeutic methods, with higher efficiency and lower side effects. Antimicrobial peptides (AMPs) are found in the innate immune system of a wide range of organisms. Identified as the most promising alternative to conventional molecules used nowadays against infections, some of them have been shown to have dual activity, both as antimicrobial and anticancer peptides (ACPs). Highly cationic and amphipathic, they have demonstrated efficacy against both conditions, with the number of nature-driven or