| 1. |
- Asemissen, Anne Marie, et al.
(author)
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Addition of histamine to interleukin 2 treatment augments type 1 T-cell responses in patients with melanoma in vivo: immunologic results from a randomized clinical trial of interleukin 2 with or without histamine (MP 104)
- 2005
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In: Clin Cancer Res. - 1078-0432. ; 11:1, s. 290-7
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Journal article (peer-reviewed)abstract
- PURPOSE: Preclinical investigations suggest that histamine dihydrochloride (HDC) protects T cells and natural killer cells from inhibition by monocyte-derived reactive oxygen metabolites and synergizes with interleukin (IL) 2 in inducing T-cell activation. Here, we investigate whether this mechanism is operational in patients with melanoma treated with HDC as an adjunct to IL-2. EXPERIMENTAL DESIGN: Melanoma patients having liver metastases were treated with IL-2 with or without HDC within a randomized, multicenter, phase III trial. The effect of HDC on type 1 and type 2 T-cell cytokine production was investigated in peripheral blood samples from 19 patients with the use of intracellular cytokine flow cytometry. Melanoma-specific T-cell responses were analyzed in eight HLA-A2-positive patients. RESULTS: Frequencies of CD3+ T cells producing IFN-gamma (type 1 T cells) in response to phorbol myristate acetate/ionomycin increased (median, 1.8-fold) in patients receiving IL-2 plus HDC but not in those receiving IL-2 alone (P < 0.01 for comparison between arms). In contrast, the number of IL-13-producing type 2 T cells that increased in patients after treatment with IL-2 was not modulated by HDC. Melanoma- and tyrosinase-specific IFN-gamma and IL-13-producing T cells were detected in two of four HLA-A2-positive patients with melanoma following treatment with HDC + IL-2. CONCLUSIONS: Treatment of patients with stage IV melanoma with HDC in combination with IL-2 increases type 1 T-cell responses and may promote induction of melanoma-specific T cells. These effects are of relevance for tumor immunotherapy and provide a potential mechanism for the clinical efficacy of HDC added to IL-2.
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| 2. |
- Eckhard, Ulrich, et al.
(author)
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Discovery of a proteolytic flagellin family in diverse bacterial phyla that assembles enzymatically active flagella
- 2017
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Journal article (peer-reviewed)abstract
- Bacterial flagella are cell locomotion and occasional adhesion organelles composed primarily of the polymeric protein flagellin, but to date have not been associated with any enzymatic function. Here, we report the bioinformatics-driven discovery of a class of enzymatic flagellins that assemble to form proteolytically active flagella. Originating by a metallopeptidase insertion into the central flagellin hypervariable region, this flagellin family has expanded to at least 74 bacterial species. In the pathogen, Clostridium haemolyticum, metallopeptidase-containing flagellin (which we termed flagellinolysin) is the second most abundant protein in the flagella and is localized to the extracellular flagellar surface. Purified flagellar filaments and recombinant flagellin exhibit proteolytic activity, cleaving nearly 1000 different peptides. With similar to 20,000 flagellin copies per similar to 10-mu m flagella this assembles the largest proteolytic complex known. Flagellum-mediated extracellular proteolysis expands our understanding of the functional plasticity of bacterial flagella, revealing this family as enzymatic biopolymers that mediate interactions with diverse peptide substrates.
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| 3. |
- Guo, Xiaohu, et al.
(author)
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Structure and mechanism of a phage-encoded SAM lyase revises catalytic function of enzyme family
- 2021
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In: eLIFE. - : eLife Sciences Publications Ltd. - 2050-084X. ; 10
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Journal article (peer-reviewed)abstract
- The first S-adenosyl methionine (SAM) degrading enzyme (SAMase) was discovered in bacteriophage T3, as a counter-defense against the bacterial restriction-modification system, and annotated as a SAM hydrolase forming 5’-methyl-thioadenosine (MTA) and L-homoserine. From environmental phages, we recently discovered three SAMases with barely detectable sequence similarity to T3 SAMase and without homology to proteins of known structure. Here, we present the very first phage SAMase structures, in complex with a substrate analogue and the product MTA. The structure shows a trimer of alpha–beta sandwiches similar to the GlnB-like superfamily, with active sites formed at the trimer interfaces. Quantum-mechanical calculations, thin-layer chromatography, and nuclear magnetic resonance spectroscopy demonstrate that this family of enzymes are not hydrolases but lyases forming MTA and L-homoserine lactone in a unimolecular reaction mechanism. Sequence analysis and in vitro and in vivo mutagenesis support that T3 SAMase belongs to the same structural family and utilizes the same reaction mechanism.
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| 4. |
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| 5. |
- Gustafsson, Robert, et al.
(author)
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Structure and Characterization of Phosphoglucomutase 5 from Atlantic and Baltic Herring : An Inactive Enzyme with Intact Substrate Binding
- 2020
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In: Biomolecules. - : MDPI AG. - 2218-273X. ; 10:12
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Journal article (peer-reviewed)abstract
- Phosphoglucomutase 5 (PGM5) in humans is known as a structural muscle protein without enzymatic activity, but detailed understanding of its function is lacking. PGM5 belongs to the alpha-D-phosphohexomutase family and is closely related to the enzymatically active metabolic enzyme PGM1. In the Atlantic herring, Clupea harengus, PGM5 is one of the genes strongly associated with ecological adaptation to the brackish Baltic Sea. We here present the first crystal structures of PGM5, from the Atlantic and Baltic herring, diering by a single substitution Ala330Val. The structure of PGM5 is overall highly similar to structures of PGM1. The structure of the Baltic herring PGM5 in complex with the substrate glucose-1-phosphate shows conserved substrate binding and active site compared to human PGM1, but both PGM5 variants lack phosphoglucomutase activity under the tested conditions. Structure comparison and sequence analysis of PGM5 and PGM1 from fish and mammals suggest that the lacking enzymatic activity of PGM5 is related to dierences in active-site loops that are important for flipping of the reaction intermediate. The Ala330Val substitution does not alter structure or biophysical properties of PGM5 but, due to its surface-exposed location, could affect interactions with protein-binding partners.
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| 6. |
- Jerlström-Hultqvist, Jon, 1982-, et al.
(author)
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A bacteriophage enzyme induces bacterial metabolic perturbation that confers a novel promiscuous function
- 2018
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In: Nature Ecology & Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 2:8, s. 1321-1330
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Journal article (peer-reviewed)abstract
- One key concept in the evolution of new functions is the ability of enzymes to perform promiscuous side-reactions that serve as a source of novelty that may become beneficial under certain conditions. Here, we identify a mechanism where a bacteriophage-encoded enzyme introduces novelty by inducing expression of a promiscuous bacterial enzyme. By screening for bacteriophage DNA that rescued an auxotrophic Escherichia coli mutant carrying a deletion of the ilvA gene, we show that bacteriophage-encoded S-adenosylmethionine (SAM) hydrolases reduce SAM levels. Through this perturbation of bacterial metabolism, expression of the promiscuous bacterial enzyme MetB is increased, which in turn complements the absence of IlvA. These results demonstrate how foreign DNA can increase the metabolic capacity of bacteria, not only by transfer of bona fide new genes, but also by bringing cryptic bacterial functions to light via perturbations of cellular physiology.
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| 7. |
- Lichtenthaler, Ulrich, et al.
(author)
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Retracted: Technology commercialization intelligence : organizational antecedents and performance consequences
- 2009
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In: Technological forecasting & social change. - : Elsevier BV. - 0040-1625 .- 1873-5509. ; 76:3, s. 301-315
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Journal article (peer-reviewed)abstract
- External technology commercialization, e.g., by means of technology licensing, has recently gained in importance. Despite imperfections in technology markets, out-licensing constitutes a major technology commercialization channel. Although the identification of licensing opportunities represents a significant managerial challenge, prior research has relatively neglected these activities. Therefore, we develop the concept of ‘technology commercialization intelligence' (TCI), which refers to the observation of a firm's environment with particular focus on identifying technology licensing opportunities. Grounded in a dynamic capabilities perspective, we test five hypotheses regarding organizational antecedents and performance consequences of TCI, drawing on data from a survey of 152 companies. The empirical findings provide strong support for the importance of the TCI concept. The findings deepen our understanding of the discrepancies between successful pioneering firms active in technology licensing and many others being less successful. The results have major implications for technology exploitation in open innovation processes.
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| 8. |
- Marino, Giada, et al.
(author)
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Family-wide characterization of Matrix Metallo-proteinases from Arabidopsis thaliana reveals their distinct proteolytic activity and cleavage site specificity.
- 2014
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In: Biochemical Journal. - : Biochemical Journal. - 0264-6021 .- 1470-8728. ; 457:2, s. 335-346
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Journal article (peer-reviewed)abstract
- Matrix metalloproteases (MMPs) are a family of zinc-dependent endopeptidases widely distributed throughout all kingdoms of life. In mammals, MMPs play key roles in many physiological and pathological processes including remodeling of the extracellular matrix. In the genome of the annual plant Arabidopsis thaliana five MMP-like proteins (At-MMPs) are encoded, but their function is unknown. Previous work on these enzymes was limited to gene expression analysis, and so far proteolytic activity has been shown only for At1-MMP. We expressed and purified the catalytic domains of all five At-MMPs as His-tagged proteins in E.coli to delineate the biochemical differences and similarities among the Arabidopsis MMP family members. We demonstrate that all five recombinant At-MMPs are active proteases with distinct preferences for different protease substrates. Furthermore, we performed a family-wide characterization of their biochemical properties and highlight similarities and differences in their cleavage site specificities as well as pH- and temperature dependent activities. Detailed analysis of their sequence specificity using Proteomic Identification of protease Cleavage Sites (PICS) revealed profiles similar to human MMPs with the exception of At5-MMP; homology models of the At-MMP catalytic domains supported these results. Our results suggest that each At-MMP may be involved in different proteolytic processes during plant growth and development.
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| 9. |
- Nielsen, Rasmus J., et al.
(author)
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Integrated ecological–economic fisheries models—Evaluation, review and challenges for implementation
- 2018
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In: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 19:1, s. 1-29
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Research review (peer-reviewed)abstract
- Marine ecosystems evolve under many interconnected and area-specific pressures. To fulfil society's intensifying and diversifying needs while ensuring ecologically sustainable development, more effective marine spatial planning and broader-scope management of marine resources is necessary. Integrated ecological–economic fisheries models (IEEFMs) of marine systems are needed to evaluate impacts and sustainability of potential management actions and understand, and anticipate ecological, economic and social dynamics at a range of scales from local to national and regional. To make these models most effective, it is important to determine how model characteristics and methods of communicating results influence the model implementation, the nature of the advice that can be provided and the impact on decisions taken by managers. This article presents a global review and comparative evaluation of 35 IEEFMs applied to marine fisheries and marine ecosystem resources to identify the characteristics that determine their usefulness, effectiveness and implementation. The focus is on fully integrated models that allow for feedbacks between ecological and human processes although not all the models reviewed achieve that. Modellers must invest more time to make models user friendly and to participate in management fora where models and model results can be explained and discussed. Such involvement is beneficial to all parties, leading to improvement of models and more effective implementation of advice, but demands substantial resources which must be built into the governance process. It takes time to develop effective processes for using IEEFMs requiring a long-term commitment to integrating multidisciplinary modelling advice into management decision-making.
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