Search results for "ANTIMICROBIAL PEPTIDES"
showing 10 items of 76 documents
Rational Design of a Carrier Protein for the Production of Recombinant Toxic Peptides in Escherichia coli
2016
Commercial uses of bioactive peptides require low cost, effective methods for their production. We developed a new carrier protein for high yield production of recombinant peptides in Escherichia coli very well suited for the production of toxic peptides like antimicrobial peptides. GKY20, a short antimicrobial peptide derived from the C-terminus of human thrombin, was fused to the C-terminus of Onconase, a small ribonuclease (104 amino acids), which efficiently drove the peptide into inclusion bodies with very high expression levels (about 200-250 mg/L). After purification of the fusion protein by immobilized metal ion affinity chromatography, peptide was obtained by chemical cleavage in d…
Stabilisation of mixed peptide/lipid complexes in selective antifungal hexapeptides
2004
AbstractThe design of antimicrobial peptides could have benefited from structural studies of known peptides having specific activity against targetmicrobes, but not toward other microorganisms. We have previously reported the identification of a series of peptides (PAF-series) activeagainst certain postharvest fungal phytopathogens, and devoid of toxicity towards E. coli and S. cerevisiae [Lo´pez-Garci´a et al. Appl.Environ. Microbiol. 68 (2002) 2453]. The peptides inhibited the conidia germination and hyphal growth. Here, we present a comparativestructural characterisation of selected PAF peptides obtained by single-amino-acid replacement, which differ in biological activity. Thepeptides w…
Identification of the Gene Repertoire of the IMD Pathway and Expression of Antimicrobial Peptide Genes in Several Tissues and Hemolymph of the Cockro…
2022
This article belongs to the Special Issue Antimicrobial Peptides and Immunology.
Echinoderm Antimicrobial Peptides to Contrast Human Pathogens
2013
Increased attention has been focused in marine invertebrates as a source of bioactive molecules for biomedical applications. Many bioactive molecules are part of the innate immune system. Some more recently isolated compounds, mainly from sea urchin and sea cucumber are antimicrobial peptides (AMP) active against Gram positive, Gram negative and fungi. In this review we described the most recent studies on AMP isolated from echinoderms. The AMP are little peptides <10 kDa with cationic charge and amphipathic structure. Recently, it was demonstrated that in the coelomocyte lysates of Paracentrotus. lividus and Holothuria tubulosa AMP are present with activity against staphylococcal and Pseud…
Antimicrobial peptides from echinoderms as antibiofilm agents: a natural strategy to combat bacterial infections
2014
AbstractIncreased attention has been focused on marine invertebrates as a source of bioactive molecules for biomedical applications. Many bioactive molecules are part of the innate immune system. Some more recently isolated compounds, mainly from the sea urchin and the sea cucumber, are antimicrobial peptides (AMPs) active against Gram-positive and Gram-negative bacteria, and fungi. In this review we described the most recent studies on AMPs isolated from echinoderms. AMPs are small peptides (< 10 kDa) with cationic charge and amphipathic structure. Recently, it was demonstrated that in the coelomocyte lysates of Paracentrotus lividus and Holothuria tubulosa, AMPs possess activity against s…
The potential of antimicrobial peptides isolated from freshwater crayfish species in new drug development: A review
2021
Abstract The much-publicised increased resistance of pathogenic bacteria to conventional antibiotics has focused research effort on the characterization of new antimicrobial drugs. In this context, antimicrobial peptides (AMPs) extracted from animals are considered a promising alternative to conventional antibiotics. In recent years, freshwater crayfish species have emerged as an important source of bioactive compounds. In fact, these invertebrates rely on an innate immune system based on cellular responses and on the production of important effectors in the haemolymph, such as AMPs, which are produced and stored in granules in haemocytes and released after stimulation. These effectors are …
Localization of antimicrobial peptides in the tunic of Ciona intestinalis (Ascidiacea, Tunicata) and their involvement in local inflammatory-like rea…
2011
AbstractTunicates comprising a wide variety of different species synthesize antimicrobial peptides as important effector molecules of the innate immune system. Recently, two putative gene families coding for antimicrobial peptides were identified in the expressed sequence tag database of the tunicate Ciona intestinalis. Two synthetic peptides representing the cationic core region of one member of each of the families displayed potent antibacterial and antifungal activities. Moreover, the natural peptides were demonstrated to be synthesized and stored in distinct hemocyte types. Here, we investigated the presence of these natural peptides, namely Ci-MAM-A and Ci-PAP-A, in the tunic of C. int…
Immune mediators of sea-cucumber Holothuria tubulosa (Echinodermata) as source of novel antimicrobial and anti-staphylococcal biofilm agents
2013
The present study aims to investigate coelomocytes, immune mediators cells in the echinoderm Holothuria tubulosa, as an unusual source of antimicrobial and antibiofilm agents. The activity of the 5kDa peptide fraction of the cytosol from H. tubulosa coelomocytes (5-HCC) was tested against a reference group of Gram-negative and Gram-positive human pathogens. Minimal inhibitory concentrations (MICs) ranging from 125 to 500 mg/ml were determined against tested strains. The observed biological activity of 5-HCC could be due to two novel peptides, identified by capillary RP-HPLC/nESI-MS/MS, which present the common chemical-physical characteristics of antimicrobial peptides. Such peptides were c…
Identification, cloning and environmental factors modulation of a αβ defensin from the lessepsian invasive mussel Brachidontes pharaonis (Bivalvia: M…
2015
International audience; Immunological effectors of invasive species playing a role in addressing new colonization are still poorly studied. In the present study the cDNA sequence of the defensin from a Lessepsian invasive species, the Red Sea mussel Brachidontes pharaonis, was cloned using RACE method. Defensins are a class of widely known antimicrobial peptides (AMPs), oligopeptides with a broad spectrum of targeted organisms ranging from viruses to parasites. Analysis of BpDef sequence (262 bp) revealed the presence of an ORF coding for 81 amino acids. The full-length amino acid sequence showed the highest similarity to antimicrobial peptides MGD1 and MGD2 sequence from Mytilus galloprovi…
Temporal patterns in immune responses to a range of microbial insults (Tenebrio molitor).
2008
8 pages; International audience; Much work has elucidated the pathways and mechanisms involved in the production of insect immune effector systems. However, the temporal nature of these responses with respect to different immune insults is less well understood. This study investigated the magnitude and temporal variation in phenoloxidase and antimicrobial activity in the mealworm beetle Tenebrio molitor in response to a number of different synthetic and real immune elicitors. We found that antimicrobial activity in haemolymph increased rapidly during the first 48h after a challenge and was maintained at high levels for at least 14 days. There was no difference in the magnitude of responses …