8 research outputs found

    Identification and Functional Characterization of a Novel Insecticidal Decapeptide from the Myrmicine Ant Manica rubida

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    Ant venoms contain many small, linear peptides, an untapped source of bioactive peptide toxins. The control of agricultural insect pests currently depends primarily on chemical insecticides, but their intensive use damages the environment and human health, and encourages the emergence of resistant pest populations. This has promoted interest in animal venoms as a source of alternative, environmentally-friendly bio-insecticides. We tested the crude venom of the predatory ant, Manica rubida, and observed severe fitness costs in the parthenogenetic pea aphid (Acyrthosiphon pisum), a common agricultural pest. Therefore, we explored the M. rubida venom peptidome and identified a novel decapeptide U-MYRTX-MANr1 (NH2-IDPKVLESLV-CONH2) using a combination of Edman degradation and de novo peptide sequencing. Although this myrmicitoxin was inactive against bacteria and fungi, it reduced aphid survival and reproduction. Furthermore, both crude venom and U-MYRTX-MANr1 reversibly paralyzed injected aphids and induced a loss of body fluids. Components of M. rubida venom may act on various biological targets including ion channels and hemolymph coagulation proteins, as previously shown for other ant venom toxins. The remarkable insecticidal activity of M. rubida venom suggests it may be a promising source of additional bio-insecticide leads

    Proteomic Analysis of the Venom from the Ruby Ant <i>Myrmica rubra</i> and the Isolation of a Novel Insecticidal Decapeptide

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    Ants are a biodiverse group of insects that have evolved toxic venom containing many undiscovered bioactive molecules. In this study, we found that the venom of the ruby ant Myrmica rubra is a rich source of peptides. LC-MS analysis revealed the presence of 142 different peptides varying in molecular weight, sequence length, and hydrophobicity. One of the most abundant peaks was selected for further biochemical and functional characterization. Combined Edman degradation and de novo peptide sequencing revealed the presence of a novel decapeptide (myrmicitoxin) with the amino acid sequence NH2-IDPKLLESLA-CONH2. The decapeptide was named U-MYRTX-MRArub1 and verified against a synthetic standard. The amidated peptide was tested in a synthetic form to determine the antimicrobial activity towards the bacterial pathogens and insecticidal potential against pea aphids (Acyrthosiphon pisum). This peptide did not show antimicrobial activity but it significantly reduced the survival of aphids. It also increased the sensitivity of the aphids to two commonly used chemical insecticides (imidacloprid and methomyl). Since ant venom research is still in its infancy, the findings of this first study on venom peptides derived from M. rubra highlight these insects as an important and rich source for discovery of novel lead structures with potential application in pest control

    Venomics of the Central European Myrmicine Ants Myrmica rubra and Myrmica ruginodis

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    Animal venoms are a rich source of novel biomolecules with potential applications in medicine and agriculture. Ants are one of the most species-rich lineages of venomous animals. However, only a fraction of their biodiversity has been studied so far. Here, we investigated the venom components of two myrmicine (subfamily Myrmicinae) ants: Myrmica rubra and Myrmica ruginodis. We applied a venomics workflow based on proteotranscriptomics and found that the venoms of both species are composed of several protein classes, including venom serine proteases, cysteine-rich secretory protein, antigen 5 and pathogenesis-related 1 (CAP) superfamily proteins, Kunitz-type serine protease inhibitors and venom acid phosphatases. Several of these protein classes are known venom allergens, and for the first time we detected phospholipase A1 in the venom of M. ruginodis. We also identified two novel epidermal growth factor (EGF) family toxins in the M. ruginodis venom proteome and an array of additional EGF-like toxins in the venom gland transcriptomes of both species. These are similar to known toxins from the related myrmicine ant, Manica rubida, and the myrmecine (subfamily Myrmeciinae) Australian red bulldog ant Myrmecia gullosa, and are possibly deployed as weapons in defensive scenarios or to subdue prey. Our work suggests that M.rubra and M. ruginodis venoms contain many enzymes and other high-molecular-weight proteins that cause cell damage. Nevertheless, the presence of EGF-like toxins suggests that myrmicine ants have also recruited smaller peptide components into their venom arsenal. Although little is known about the bioactivity and function of EGF-like toxins, their presence in myrmicine and myrmecine ants suggests they play a key role in the venom systems of the superfamily Formicoidea. Our work adds to the emerging picture of ant venoms as a source of novel bioactive molecules and highlights the need to incorporate such taxa in future venom bioprospecting programs

    Big Data für Versicherungen. Proceedings zum 21. Kölner Versicherungssymposium am 3.11.2016 in Köln

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    Aufgrund der schnellen technologischen Entwicklungen und den damit einhergehenden erweiterten Möglichkeiten hat für den Begriff „Big Data“ eine starke Begriffserweiterung stattgefunden – insbesondere im Dreiklang Digitalisierung / Big Data / Cloud Computing (DBC). „Big Data“ im weiteren Sinn umfasst inzwischen mindesten die Themenfelder IT & Prozesse, Methoden & Modellierung, Produktentwicklung & Kundenmanagement sowie Recht & Datenschutz. Wegen der hohen Bedeutung haben die Forschungsbereiche des ivwKöln für 2016 „Big Data“ als übergreifendes Forschungsthema gewählt. Im 21. Kölner Versicherungs-symposium wurde daher das Themenfeld in seiner Vielschichtigkeit von Referenten aus mehreren Fachrichtungen skizziert.The Caused by the technological development and the corresponding extended possibilities, an ex-tension of term “Big Data” has occurred – especially in the context of Digitalization / Big Data / Cloud Computing (DBC). In an extended definition, “Big Data” covers at least the aspects “IT & Processes”, “Methods & Modeling”, “Product Development & Client Management” as well as “Legal Aspects & Data Protection”. Because of the high relevance, the research centers of the Cologne Institute of Insurance (ivwKöln) have chosen “Big Data” as a common research topic. At the 21th Cologne Insurance Symposium, “Big Data” has been treated by speakers representing the various aspects of this topic

    A New Citrinin Derivative from the Indonesian Marine Sponge-Associated Fungus Penicillium citrinum

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    Sponge-associated fungi are attractive targets for the isolation of bioactive natural products with different pharmaceutical purposes. In this investigation, 20 fungi were isolated from 10 different sponge specimens. One isolate, the fungus Penicillium citrinum strain WK-P9, showed activity against Bacillus subtilis JH642 when cultivated in malt extract medium. One new and three known citrinin derivatives were isolated from the extract of this fungus. The structures were elucidated by 1D and 2D NMR spectroscopy, as well as LC-HRMS. Their antibacterial activity against a set of common human pathogenic bacteria and fungi was tested. Compound 2 showed moderate activity against Mycobacterium smegmatis ATCC607 with a minimum inhibitory concentration (MIC) of 32 &micro;g/mL. Compound 4 exhibited moderate growth inhibition against Bacillus subtilis JH642, B. megaterium DSM32, and M. smegmatis ATCC607 with MICs of 16, 16, and 32 &micro;g/mL, respectively. Furthermore, weak activities of 64 &micro;g/mL against B. subtilis DSM10 and S. aureus ATCC25923 were observed for compound 4

    The Retro-Diels-Alder Reaction Part II. Dienophiles with One or More Heteroatom

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