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Study of antimicrobial peptide induction in Brassica napus
Shevchenko, I. ; Neubauerová, Tereza ; Macková, Martina ; Macek, Tomáš
Development of cheap, effective and environmentally friendly protection of industrial plants is a key problem of mankind, where using of antimicrobial peptides could be a reasonable solution. As a source for isolation of these peptides canola (Brassica napus) was chosen, which was treated by functional analog of salicylic acid – benzothiadiazole (BTH) – to stimulate the immune system. To isolate the responsible antimicrobial peptides, crude buffer extract was obtained. Next steps were precipitation, centrifugation and molecular weight filtration. The further isolation procedure comprised hexane extraction, SPE-C18 (Solid Phase Extraction) to separate hydrophobic and hydrophilic fractions and reversed-phase chromatography. Antimicrobial activity was tested by diffusion method. Fractions were tested on gram-positive and gram-negative bacteria and on yeast Candida scotii.
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Isolation and study of the properties of recombinant pseudoosmotin
Richterová, K. ; Nováková, Martina ; Antošová, Z. ; Neubauerová, Tereza ; Macková, Martina
Antimicrobial peptides represent new clinical compounds with antimicrobial action and they could participate in solving the problem of ever-increasing resistance of microorganisms to the traditional antibiotics. The aim of this work was to study optimal conditions for expression, isolation and purification of recombinant pseudoosmotin from Escherichia coli BL21 (DE3). Pseudoosmotin was isolated from membrane fraction of bacteria and was purified by the affinity chromatography using Ni-NTA. Isolated pseudoosmotin did not show antimicrobial activity against studied microorganisms.
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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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