Search for dissertations about: "cyclotides"

Showing result 1 - 5 of 11 swedish dissertations containing the word cyclotides.

  1. 1. Cyclotides : Tuning Parameters Toward Their Use in Drug Design

    Author : Mariamawit Yonathan Yeshak; Ulf Göransson; Lars Bohlin; Kaleab Asres; Robert Kiss; Uppsala universitet; []
    Keywords : cyclotide; Viola abyssinica; Viola odorata; Extraction; Violaceae; vaby; cytotoxic; genotoxic; cell penetrating; microautoradiography; LC-MS; comet assay; cycloviolacin O2; Farmakognosi; Pharmacognosy;

    Abstract : Cyclotides are plant proteins with a unique topology, defined as the cyclic cystine knot motif. The motif endows cyclotides with exceptional chemical and biological stability. They also exhibit a wide range of biological activities including insecticidal, cytotoxic, anti-HIV and antimicrobial effects. READ MORE

  2. 2. Cyclotides evolve : Studies on their natural distribution, structural diversity, and activity

    Author : Sungkyu Park; Göransson Ulf; Lars Bohlin; Mohamed Marahiel; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; cyclotide; cyclic cystine knot; evolution; peptide synthesis; chemical ligation; QSAR; Viola; Violaceae; phylogeny; Farmakognosi; Pharmacognosy;

    Abstract : The cyclotides are a family of naturally occurring peptides characterized by cyclic cystine knot (CCK) structural motif, which comprises a cyclic head-to-tail backbone featuring six conserved cysteine residues that form three disulfide bonds. This unique structural motif makes cyclotides exceptionally resistant to chemical, thermal and enzymatic degradation. READ MORE

  3. 3. Cytotoxic Cyclotides : Structure, Activity, and Mode of Action

    Author : Erika Svangård; Per Claeson; Lars Bohlin; Ulf Göransson; John H. Cardellina II; Uppsala universitet; []
    Keywords : MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Pharmacognosy; cyclotide; cytotoxic; cancer; cyclic cystine knot; Viola; Violaceae; liposome; hollow fibre; homology modelling; mass spectrometry; amphipathic; structure–activity; tumour; membrane disruption; necrosis; Farmakognosi; Pharmacognosy; Farmakognosi;

    Abstract : Cyclotides are small cyclic plant proteins, and this thesis addresses their cytotoxic structure-activity properties and their mode of action on human cancer cell lines. Cyclotides were isolated from Viola odorata and Viola tricolor; three novel cyclotide sequences and two known sequences, but of new origin, were identified using mass spectrometry, amino acid analysis, and Edman degradation. READ MORE

  4. 4. Interaction of cyclotides and bacteria : A study of the cyclotide action and the bacterial reaction

    Author : Sohaib Zafar Malik; Ulf Göransson; Dan Andersson; William Shafer; Uppsala universitet; []
    Keywords : Cyclotides; cycloviolacin O2; cycloviolacin O3; cycloviolacin O19; antimicrobial peptide resistance; Salmonella enterica; Eschericia coli; Viola odorata; Farmakognosi; Pharmacognosy;

    Abstract : The growing problem of antibiotic resistance and the lack of promising prospective antibiotics have forced us to search for new classes of antibiotics. Among the candidates to develop into future antibacterials are antimicrobial peptides (AMPs). READ MORE

  5. 5. Engineering of the Ultra-stable Cystine Knot Framework of Microproteins : Design, Chemical Synthesis and Structural Studies

    Author : Teshome Leta Aboye; Ulf Göransson; Julio A. Camarero; Uppsala universitet; []
    Keywords : MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; cyclotides; cystine knot; protein engineering; NMR; solid phase; disulfide rich; ultra-stable; microprotein; PHARMACY; FARMACI; Medicinal Chemistry; Läkemedelskemi;

    Abstract : Ultra-stable cystine knotted microproteins, in which two disulfides and their connecting backbones form a circle that is penetrated by the third disulfide bonds, have attracted high interest due to their resistance to degradation in vitro and potential for the development of peptide drugs. This thesis gives new insights into engineering of that framework of microproteins, including approaches to their chemical synthesis, backbone engineering, structural and biological evaluations. READ MORE