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Isolation of antimicrobial peptides and proteins from tomato
Králová, M. ; Šanda, Miloslav ; Macková, M. ; Macek, Tomáš
Recent emerging problem is occurrence of multiresistant pathogens. This inconvenience makes people to search for new antimicrobials. One of possible ways is looking for natural antimicrobial peptides. In our project, green tissues of tomato (Solanum lycopersicum) were chosen for isolation of such peptides. Extracts obtained were fractionated by solid phase extraction and liquid chromatography. Antimicrobial activities were tested on model microorganisms. Several fractions exhibited antimicrobial activity against bacteria and fungi. In the extracts, precursors of two antifungal proteins were identified.
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Analysis of antimicrobial peptides by capillary electrophoresis
Ehala, Sille ; Niederhafner, Petr ; Čeřovský, Václav ; Řezanka, P. ; Sýkora, D. ; Král, V. ; Kašička, Václav
Capillary electrophoresis was used for the purity degree determination of new antimicrobial peptides: octadecapeptide melectin and tetradecapeptide mastoparan PDD-B, and their synthetic analogues. Besides, four semiempirical models correlating electrophoretic mobilities of these peptides with their charge and size (relative molecular mass) were applied to predict their probable structures in solution. Additionally, capillaries coated with gold nanoparticles were employed for the separation of mixtures of antimicrobial peptides.
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Design of stable antimicrobial peptides through hydrocarbon stapling
Chapuis, Hubert Jean ; Slaninová, Jiřina ; Monincová, Lenka ; Bednárová, Lucie ; Čeřovský, Václav
From the venom of wild bee Lasioglossum laticeps we have recently isolated novel antimicrobial peptides named lasioglossins. One of them, LL-III (VNWKKILGKIIKVVK-NH2), is an amphipathic α-helical peptide which shows strong antimicrobial properties and a low hemolytic activity. We anticipated that the incorporation of an all-hydrocarbon staple (bridge) into the LL-III sequence could increase its propensity to form an α-helix and lead to an improvement of its proteolytic stability as well as increase the antimicrobial activity. LL-III analogs featuring olefinic side chains in various positions were prepared by solid phase peptide synthesis. Ring closing olefin metatheses catalyzed by Grubbs-I catalyst were carried out on the solid support, either between i and i+4 positions or between i and i+7 positions.
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Characterization of a defensin of the tick \kur{Dermacentor marginatus}
LEŠTINOVÁ, Kateřina
Antimicrobial peptides (AMPs), as a part of innate immune system of ticks and other living organisms, are able to eliminate pathogens. In ticks the most important group of AMPs is defensin family. In this work, defensin from the tick D. marginatus was studied. The defensin gene was isolated from D. marginatus fed females. Using RT-PCR the gene expression was detected in salivary glands and mitgut. Recombinant protein was expressed in the procaryotic expression system, purified and tested for its antimicrobial activity. Specific polyclonal rabbit antibodies (anti DR IgG) were prepared and tested for their specifity and sensitivity.
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Isolation of the antimicrobial peptide gene (defensin) from the hard tick \kur{Ixodes ricinus}, challenged by the pathogen infection
SKLADANÁ, Veronika
Antimicrobial peptides are major components of the innate immune response of epithelial cells. In hematophagous organisms, which acts as vectors of parasitic diseases, in particular Lyme borreliosis, the gut pathogen induce the expression of defensin, that provide the first barier of host defence. This raises the posibility that defensin may play a key role in the development of parasitic infection. The gene expressed in midgut was isolated from cDNA of the hard tick, Ixodes ricinus. The gene is coding the protein, that is produced and secreted during tick infection, and is known as defensin. Expression of the gene for defensin (224 bp) was induced by the pathogen. The gene was cloned into bacterial expression system.
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Plant peptides and proteins with antimicrobial activities and possibilities of their application
LORENC, František
This work deals with antimicrobial peptides and proteins in plants. Antimicrobial peptides form one part of non-specific immunity most eukaryotic and prokaryotic organisms. Their primary function is to eliminate the attacks of microbial pathogens, by which are the target organisms exposured. These proteins have low molecular weight. Most of them form a group of PR (Pathogenesis-related) proteins. Thanks to their antimicrobial effects have the antimicrobial peptides and proteins a great potential in pharmaceutical industry, medicine and biotechnology or in protection against plant diseases and also in other applications. The aim of this work is to describe the primary fission of plant antimicrobial peptides and proteins, the mechanisms of their antimicrobial action and characteristics of the main groups of PR-proteins. In the end of this work is described the current research and applications and potential uses in the future.
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Novel biologically active peptides from the venom of the solitary bee Macropis fulvipes (HYMENOPTERA: MELITTIDAE)
Monincová, Lenka ; Slaninová, Jiřina ; Voburka, Zdeněk ; Hovorka, Oldřich ; Fučík, Vladimír ; Borovičková, Lenka ; Bednárová, Lucie ; Buděšínský, Miloš ; Straka, J. ; Čeřovský, Václav
Two peptides (macropine-1 and macropin-2) were isolated, their structure determined by Edman degradation and mass spectrometry, which exhibited potent antimicrobial activity against both Gram-positive and -negative bacteria and moderate hemolytic activity against rat erythrocytes. We prepared several MAC-1 analogs to study the effect of their structure on antimicrobial and hemolytic activities.
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New peptides with antimicrobial activity isolated from the venom of the bumblebee Bombus pascuorum (Hymenoptera: Apidae)
Ježek, Rudolf ; Janechová, D. ; Cvačka, Josef ; Slaninová, Jiřina ; Voburka, Zdeněk ; Hovorka, Oldřich ; Fučík, Vladimír ; Borovičková, Lenka ; Maloň, Petr ; Čeřovský, Václav
Six new heptadecapeptides were isolated and synthesized by standard Fmoc solid phase peptide synthesistogether with several structural analogues. Antimicrobial activities were correlated with the peptides hydrophobicity, hydrophobic moment, alpha-helicity and HPLC retention time.
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