29 results on '"Markus Kaufmann"'
Search Results
2. Überfällige ärztliche Hilfen
- Author
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Markus Kaufmann and Peter Lehmann
- Subjects
business.industry ,Medicine ,General Medicine ,business - Published
- 2019
3. Diagnostische Grundlagen
- Author
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Marianne Abele-Horn, Markus Kaufmann, and Benno Stinner
- Published
- 2021
4. Stationärer Entzug, der Start in ein suchtfreies Leben? Arbeitsfeld Entzug und Entwöhnung
- Author
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Markus Kaufmann
- Abstract
ZusammenfassungDas therapeutische Angebot der Klinik Zugersee beinhaltet Behandlungen für sämtliche Formen psychischer Erkrankungen (z. B. Depressionen, Ängste, Psychosen, Abhängigkeitserkrankungen und verschiedene Demenzformen) sowie psychosomatischer Erkrankungen (z. B. Schlafstörungen und Schmerzstörungen).
- Published
- 2020
5. PAX8 and MECOM are interaction partners driving ovarian cancer
- Author
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Johannes Voshol, Therese Stachyra, Alexandra Vissieres, Elisabeth Bechter, Verena Apfel, Erik Ahrné, Maria Wahle, Suzanne Chau, Ivana Moravec, Karolin Fiona Berneiser, Nathalie Carte, Tania Poetsch, Rui Lopes, Dirk Schübeler, Simon Haenni, Markus Kaufmann, Stephane Ferretti, Dirk Erdmann, Alexandra Hinniger, Marianne Bachmann Salvy, Jacques Hamon, Guglielmo Roma, Amanda Cobos-Correa, Ulrike Naumann, César Fernández, Louise Barys, Cristina Nieto-Oberhuber, Giorgio G. Galli, Melusine Bleu, Matteo Fischer, Felix Freuler, Sascha Gutmann, Kate Lawrenson, Fanny Mermet-Meillon, Tobias Schmelzle, Cecile Delmas, Laura Holzer, Marco Meyerhofer, and Ines Barbosa
- Subjects
0301 basic medicine ,Gene isoform ,MECOM ,Science ,General Physics and Astronomy ,Mice, Nude ,Locus (genetics) ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Article ,03 medical and health sciences ,PAX8 Transcription Factor ,0302 clinical medicine ,Cell Line, Tumor ,Gene expression ,medicine ,Animals ,Humans ,Protein Isoforms ,Transcription factor ,Gene ,Ovarian Neoplasms ,Gynaecological cancer ,Multidisciplinary ,General Chemistry ,medicine.disease ,Xenograft Model Antitumor Assays ,MDS1 and EVI1 Complex Locus Protein ,Tumor Burden ,Gene regulation ,Gene Expression Regulation, Neoplastic ,030104 developmental biology ,HEK293 Cells ,030220 oncology & carcinogenesis ,Cancer research ,Female ,Ovarian cancer ,PAX8 ,Protein Binding - Abstract
The transcription factor PAX8 is critical for the development of the thyroid and urogenital system. Comprehensive genomic screens furthermore indicate an additional oncogenic role for PAX8 in renal and ovarian cancers. While a plethora of PAX8-regulated genes in different contexts have been proposed, we still lack a mechanistic understanding of how PAX8 engages molecular complexes to drive disease-relevant oncogenic transcriptional programs. Here we show that protein isoforms originating from the MECOM locus form a complex with PAX8. These include MDS1-EVI1 (also called PRDM3) for which we map its interaction with PAX8 in vitro and in vivo. We show that PAX8 binds a large number of genomic sites and forms transcriptional hubs. At a subset of these, PAX8 together with PRDM3 regulates a specific gene expression module involved in adhesion and extracellular matrix. This gene module correlates with PAX8 and MECOM expression in large scale profiling of cell lines, patient-derived xenografts (PDXs) and clinical cases and stratifies gynecological cancer cases with worse prognosis. PRDM3 is amplified in ovarian cancers and we show that the MECOM locus and PAX8 sustain in vivo tumor growth, further supporting that the identified function of the MECOM locus underlies PAX8-driven oncogenic functions in ovarian cancer., Lineage-restricted transcription factor PAX8 is oncogenic in ovarian cancer cells. Here the authors show that PAX8 interacts and recruits a splice variant of the MECOM locus PRDM3 to control the gene expression module involved in adhesion and extracellular matrix, and consequently promotes ovarian tumorigenesis.
- Published
- 2020
6. Potentiale einer Service-App mit Augmented Reality in der Produktinstandhaltung
- Author
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Markus Kaufmann
- Abstract
Die Digitalisierung der Produktdokumentation eroffnet mittels Augmented Reality neue Moglichkeiten im Produktlebenszyklus, im Engineering, in der Produktion und der Produktnutzungsphase.
- Published
- 2020
7. Bioorthogonal Probes for the Study of MDM2-p53 Inhibitors in Cells and Development of High-Content Screening Assays for Drug Discovery
- Author
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Markus Kaufmann, Frédéric Baysang, Amanda Cobos-Correa, Pascal Furet, Therese-Marie Stachyra, Andreas Marzinzik, Nicole Buschmann, Pier Luca D’Alessandro, Johannes Ottl, Dimitrios Lizos, Reto Brunner, and Thomas Vorherr
- Subjects
0301 basic medicine ,Models, Molecular ,Indoles ,Drug Evaluation, Preclinical ,Antineoplastic Agents ,Biosensing Techniques ,Computational biology ,010402 general chemistry ,01 natural sciences ,Catalysis ,03 medical and health sciences ,Downregulation and upregulation ,Cell Line, Tumor ,Humans ,Mdm2 p53 ,Fluorescent Dyes ,Osteosarcoma ,Molecular Structure ,010405 organic chemistry ,Chemistry ,Drug discovery ,Proto-Oncogene Proteins c-mdm2 ,General Medicine ,General Chemistry ,Molecular biology ,0104 chemical sciences ,030104 developmental biology ,High-content screening ,Single-Cell Analysis ,Tumor Suppressor Protein p53 ,Bioorthogonal chemistry ,Cellular model ,Target binding - Abstract
To study the behavior of MDM2-p53 inhibitors in a disease-relevant cellular model, we have developed and validated a set of bioorthogonal probes that can be fluorescently labeled in cells and used in high-content screening assays. By using automated image analysis with single-cell resolution, we could visualize the intracellular target binding of compounds by co-localization and quantify target upregulation upon MDM2-p53 inhibition in an osteosarcoma model. Additionally, we developed a high-throughput assay to quantify target occupancy of non-tagged MDM2-p53 inhibitors by competition and to identify novel chemical matter. This approach could be expanded to other targets for lead discovery applications.
- Published
- 2016
8. X-ray Structures and Feasibility Assessment of CLK2 Inhibitors for Phelan-McDermid Syndrome
- Author
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Bertrand Arnaud, Marianne Uteng, Sandra Holzinger, Peter von Matt, Patrik Roethlisberger, Ivan Galimberti, Christel Guibourdenche, Felix Freuler, Simon Haenni, Markus Kaufmann, Murielle Brichet, Amanda Cobos-Correa, Christian Bergsdorf, Mario Bernhard, Andreas Lerchner, Juerg Hunziker, Valery Polyakov, Joerg Kallen, Aude Izaac, Hans-Joerg Martus, Azeddine Elhajouji, Lukas Leder, Guglielmo Roma, and Nikolaus Stiefl
- Subjects
0301 basic medicine ,Models, Molecular ,Indazoles ,In silico ,Chromosomes, Human, Pair 22 ,Chromosome Disorders ,Pharmacology ,Protein Serine-Threonine Kinases ,medicine.disease_cause ,Crystallography, X-Ray ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,CLK2 ,Structure-Activity Relationship ,Phelan-McDermid syndrome ,Drug Discovery ,medicine ,Transferase ,Humans ,General Pharmacology, Toxicology and Pharmaceutics ,Protein Kinase Inhibitors ,chemistry.chemical_classification ,Indazole ,Dose-Response Relationship, Drug ,Molecular Structure ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Protein-Tyrosine Kinases ,0104 chemical sciences ,030104 developmental biology ,Enzyme ,Micronucleus test ,Molecular Medicine ,Chromosome Deletion ,Genotoxicity - Abstract
CLK2 inhibition has been proposed as a potential mechanism to improve autism and neuronal functions in Phelan-McDermid syndrome (PMDS). Herein, the discovery of a very potent indazole CLK inhibitor series and the CLK2 X-ray structure of the most potent analogue are reported. This new indazole series was identified through a biochemical CLK2 Caliper assay screen with 30k compounds selected by an in silico approach. Novel high-resolution X-ray structures of all CLKs, including the first CLK4 X-ray structure, bound to known CLK2 inhibitor tool compounds (e.g., TG003, CX-4945), are also shown and yield insight into inhibitor selectivity in the CLK family. The efficacy of the new CLK2 inhibitors from the indazole series was demonstrated in the mouse brain slice assay, and potential safety concerns were investigated. Genotoxicity findings in the human lymphocyte micronucleus test (MNT) assay are shown by using two structurally different CLK inhibitors to reveal a major concern for pan-CLK inhibition in PMDS.
- Published
- 2018
9. The Impact of Cyclopropane Configuration on the Biological Activity of Cyclopropyl-Epothilones
- Author
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Isabel Barasoain, Fabienne Z. Gaugaz, J. Fernando Díaz, Karl-Heinz Altmann, Markus Kaufmann, Mariano Redondo-Horcajo, Amanda Cobos-Correa, Swiss National Science Foundation, ETH Zurich, Ministerio de Economía y Competitividad (España), and Comunidad de Madrid
- Subjects
Cyclopropanes ,Epothilones ,Stereochemistry ,Epoxide ,Structure-activity relationships ,Metathesis ,Microtubules ,Biochemistry ,Cell Line ,Cyclopropane ,Stereocenter ,chemistry.chemical_compound ,Drug Discovery ,Humans ,Moiety ,General Pharmacology, Toxicology and Pharmaceutics ,Cancer ,Pharmacology ,Molecular Structure ,Inhibitors ,Organic Chemistry ,Stereoselective synthesis ,Diastereomer ,chemistry ,Molecular Medicine ,Stereoselectivity - Abstract
Two cis-12,13-cyclopropyl-epothilone B variants have been synthesized, differing only in the configuration of the stereocenters at C12 and C13. The syntheses were based on a common allylic alcohol intermediate that was converted into the corresponding diastereomeric hydroxymethyl-cyclopropanes by means of stereoselective Charette cyclopropanations. Macrocyclizations were accomplished through ring-closing metathesis (RCM). Substantial differences between the two compounds were found with regard to microtubule binding affinity, antiproliferative activity and their effects on the cellular microtubule network. While the analogue with the cyclopropane moiety oriented in a corresponding way to the epoxide configuration in natural epothilones was almost equipotent with epothilone A, the other was significantly less active. Based on these findings, natural epothilone-like activity of cis-fused 12,13-cyclopropyl-epothilone analogues is tightly linked to the natural orientation of the cyclopropane moiety., K.H.A. and F.Z.G. are indebted to the Swiss National Science Foundation (SNF) (project 205320-117594) and ETH Zürich for generous financial support. J.F.D. acknowledges financial support by the Ministerio de Economia of Spain and from the Comunidad de Madrid (projects BIO2013-42984-R and S2010/BMD-2457 BIPPED, respectively).
- Published
- 2014
10. Stretchable Circuits: 3D Multifunctional Composites Based on Large-Area Stretchable Circuit with Thermoforming Technology (Adv. Electron. Mater. 8/2018)
- Author
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Markus Kaufmann, Yang Yang, Tom Martens, Linde De Vriese, Steven Van Put, Thomas Vervust, Kristof Dhaenens, Lieven Degrendele, Bjorn Vandecasteele, Tsuyoshi Sekitani, Sheila Dunphy, Lothar Mader, and Jan Vanfleteren
- Subjects
Materials science ,Composite material ,Thermoforming ,Thermoplastic composites ,Electronic, Optical and Magnetic Materials ,Electronic circuit - Published
- 2018
11. 3D Multifunctional Composites Based on Large-Area Stretchable Circuit with Thermoforming Technology
- Author
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Tom Martens, Linde De Vriese, Tsuyoshi Sekitani, Jan Vanfleteren, Lieven Degrendele, Bjorn Vandecasteele, Sheila Dunphy, Lothar Mader, Kristof Dhaenens, Thomas Vervust, Yang Yang, Markus Kaufmann, and Steven Van Put
- Subjects
Materials science ,Fabrication ,Capacitive sensing ,Electronic skin ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,Planar ,law ,Lamination ,Composite material ,0210 nano-technology ,Actuator ,Thermoforming ,Electronic circuit - Abstract
Fiber-reinforced polymer composites with integrated intelligence, such as sensors, actuators, and communication capabilities, are desirable as infrastructures for the next generation of "internet of things." However, the shape mismatch between the 3D composites and a planar electronic circuit causes difficulties in integrating electronic circuit-based intelligences. Here, an easily scalable approach, by incorporating a large-area stretchable circuit with thermoforming technology, to fabricate 3D multifunctional composites is reported. The stretchable circuit is first fabricated on a rigid and planar carrier board, then transferred and sandwiched between thermoplastic composites through lamination processes. A thermoforming step shapes the sandwiched and planar structure by heating up the encapsulating polymers beyond their glass transition temperature and pushing them and the circuit against a mold. Using the proposed process, large-sized composites with integrated matrices of light-emitting diodes (LEDs) and capacitive sensors are successfully fabricated. A giant (with a size of 0.5 m x 1 m) seven-segment display is assembled using the fabricated composites with integrated LEDs and capacitive sensors to display 128 symbols. The results demonstrate the potential of the proposed approach as a facile, reproducible, and scalable process for creating 3D multifunctional composites.
- Published
- 2018
12. Die präoperative Evaluation beim elektiven Patienten
- Author
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Markus Kaufmann and Oliver Bandschapp
- Subjects
General Medicine - Abstract
Die präoperative Evaluation dient der Risikobeurteilung des Patienten mit dem Ziel einer Risikominimierung für den anschließenden operativen Eingriff. In Abhängigkeit von Systemanamnese, Befunden und geplantem Eingriff werden bei Bedarf weitergehende Abklärungen durchgeführt. Der klinische Zustand des Patienten wird, falls nötig, optimiert und das perioperative Vorgehen geplant. Der Patient wird über Anästhesie und perioperative Periode aufgeklärt. Das Einverständnis zum vereinbarten Anästhesieverfahren wird eingeholt. Leistungsfähige Patienten ohne Risikofaktoren können dank neuer Technologien einfacher und effizienter evaluiert werden.
- Published
- 2009
13. Functional Linkages Can Reveal Protein Complexes for Structure Determination
- Author
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Thomas C. Terwilliger, Debnath Pal, Peter Bowers, Markus Kaufmann, Michael J. Strong, David Eisenberg, and Sul-Min Kim
- Subjects
Models, Molecular ,Escherichia coli Proteins ,PROTEINS ,Functional protein ,Protein Conformation ,Protein Data Bank (RCSB PDB) ,Computational biology ,computer.file_format ,Biology ,medicine.disease_cause ,Protein Data Bank ,Structural genomics ,Crystallography ,Protein structure ,Structural Biology ,medicine ,Databases, Protein ,Escherichia coli ,computer ,Molecular Biology - Abstract
SummaryIn the study of protein complexes, is there a computational method for inferring which combinations of proteins in an organism are likely to form a crystallizable complex? Here we attempt to answer this question, using the Protein Data Bank (PDB) to assess the usefulness of inferred functional protein linkages from the Prolinks database. We find that of the 242 nonredundant prokaryotic protein complexes shared between the current PDB and Prolinks, 44% (107/242) contain proteins linked at high confidence by one or more methods of computed functional linkages. Similarly, high-confidence linkages detect 47% of known Escherichia coli protein complexes, with 45% accuracy. Together these findings suggest that functional linkages will be useful in defining protein complexes for structural studies, including for structural genomics. We offer a database of inferred linkages corresponding to likely protein complexes for some 629,952 pairs of proteins in 154 prokaryotes and archaea.
- Published
- 2007
- Full Text
- View/download PDF
14. High-Throughput Screening Using iPSC-Derived Neuronal Progenitors to Identify Compounds Counteracting Epigenetic Gene Silencing in Fragile X Syndrome
- Author
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Barna D. Fodor, Amanda Cobos-Correa, Jessica Klein, Matthias Mueller, Tewis Bouwmeester, Isabelle Fruh, Anke Thiemeyer, Ulrich Schopfer, Pierre Rigo, Valerie Heidinger-Millot, Ansgar Schuffenhauer, Baltazar Gomez-Mancilla, and Markus Kaufmann
- Subjects
congenital, hereditary, and neonatal diseases and abnormalities ,Phenotypic screening ,Induced Pluripotent Stem Cells ,Drug Evaluation, Preclinical ,Context (language use) ,Computational biology ,Biology ,Biochemistry ,Analytical Chemistry ,Fragile X Mental Retardation Protein ,Neural Stem Cells ,Trinucleotide Repeats ,medicine ,Gene silencing ,Humans ,Epigenetics ,Gene Silencing ,Induced pluripotent stem cell ,Cells, Cultured ,Genetics ,Drug discovery ,medicine.disease ,High-Throughput Screening Assays ,Fragile X syndrome ,High-content screening ,Fragile X Syndrome ,Molecular Medicine ,Biotechnology - Abstract
Fragile X syndrome (FXS) is the most common form of inherited mental retardation, and it is caused in most of cases by epigenetic silencing of the Fmr1 gene. Today, no specific therapy exists for FXS, and current treatments are only directed to improve behavioral symptoms. Neuronal progenitors derived from FXS patient induced pluripotent stem cells (iPSCs) represent a unique model to study the disease and develop assays for large-scale drug discovery screens since they conserve the Fmr1 gene silenced within the disease context. We have established a high-content imaging assay to run a large-scale phenotypic screen aimed to identify compounds that reactivate the silenced Fmr1 gene. A set of 50,000 compounds was tested, including modulators of several epigenetic targets. We describe an integrated drug discovery model comprising iPSC generation, culture scale-up, and quality control and screening with a very sensitive high-content imaging assay assisted by single-cell image analysis and multiparametric data analysis based on machine learning algorithms. The screening identified several compounds that induced a weak expression of fragile X mental retardation protein (FMRP) and thus sets the basis for further large-scale screens to find candidate drugs or targets tackling the underlying mechanism of FXS with potential for therapeutic intervention.
- Published
- 2015
15. Structure of rabbit-muscle glyceraldehyde-3-phosphate dehydrogenase
- Author
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Markus G. Grütter, Anthony Anselmo, Markus Kaufmann, Wilhelm Stark, and Sandra W. Cowan-Jacob
- Subjects
Models, Molecular ,Molecular Sequence Data ,Static Electricity ,Muscle Proteins ,Dehydrogenase ,Biology ,Nicotinamide adenine dinucleotide ,Crystallography, X-Ray ,Cofactor ,chemistry.chemical_compound ,stomatognathic system ,Structural Biology ,Oxidoreductase ,Animals ,Amino Acid Sequence ,Databases, Protein ,Protein Structure, Quaternary ,Glyceraldehyde 3-phosphate dehydrogenase ,chemistry.chemical_classification ,Binding Sites ,Muscles ,Glyceraldehyde-3-Phosphate Dehydrogenases ,Cooperative binding ,General Medicine ,NAD ,Protein Structure, Tertiary ,Protein Subunits ,Enzyme ,chemistry ,Biochemistry ,biology.protein ,Rabbits ,NAD+ kinase ,Sequence Alignment ,Protein Binding - Abstract
The crystal structure of the tetrameric form of D-glyceraldehyde-3-phosphate dehydrogenase (GAPDH) isolated from rabbit muscle was solved at 2.4 A resolution after careful dynamic light-scattering experiments to find a suitable buffer for crystallization trials. The refined model has a crystallographic R factor of 20.3%. Here, the first detailed model of a mammalian GAPDH is presented. The cofactor NAD(+) (nicotinamide adenine dinucleotide) is bound to two subunits of the tetrameric enzyme, which is consistent with the negative cooperativity of NAD(+) binding to this enzyme. The structure of rabbit-muscle GAPDH is of interest because it shares 91% sequence identity with the human enzyme; human GAPDH is a potential target for the development of anti-apoptotic drugs. In addition, differences in the cofactor-binding pocket compared with the homology-model structure of GAPDH from the malaria parasite Plasmodium falciparum could be exploited in order to develop novel selective and potential antimalaria drugs.
- Published
- 2003
16. Identification of a basic surface area of the FADD death effector domain critical for apoptotic signaling
- Author
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Damir Bozic, Andreas Kohl, Christophe Briand, Jürg Tschopp, Jean-Luc Bodmer, Oliver Zerbe, Markus Kaufmann, and Markus G. Grütter
- Subjects
Models, Molecular ,Protein Conformation ,Fas-Associated Death Domain Protein ,Molecular Sequence Data ,Fas-associated death domain ,Mutant ,CASP8 and FADD-Like Apoptosis Regulating Protein ,Biophysics ,Apoptosis ,Homotypic interaction ,Caspase 8 ,Biochemistry ,Structural Biology ,Death inducing signaling complex ,Genetics ,Humans ,Amino Acid Sequence ,FADD ,Death effector domain ,Molecular Biology ,Cells, Cultured ,Adaptor Proteins, Signal Transducing ,Death domain ,Binding Sites ,biology ,Caspase 3 ,Effector ,Intracellular Signaling Peptides and Proteins ,Cell Biology ,Inhibitor protein ,Protein Structure, Tertiary ,Cell biology ,Caspases ,Mutation ,Cellular FLICE inhibitor protein ,Death-inducing signaling complex ,biology.protein ,Carrier Proteins ,Caspase-8 ,Signal Transduction - Abstract
Death effector domains (DEDs) are protein–protein interaction domains found in the death inducing signaling complex (DISC). Performing a structure-based alignment of all DED sequences we identified a region of high diversity in α-helix 3 and propose a classification of DEDs into class I DEDs typically containing a stretch of basic residues in the α-helix 3 region whereas DEDs of class II do not. Functional assays using mutants of Fas-associated death domain revealed that this basic region influences binding and recruitment of caspase-8 and cellular FLICE inhibitor protein to the DISC.
- Published
- 2002
17. Crystal Structure of the Anti-His Tag Antibody 3D5 Single-chain Fragment Complexed to its Antigen
- Author
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Kerstin Blank, Peter Lindner, Andreas Plückthun, Markus Kaufmann, Markus Tschopp, Markus G. Grütter, Annemarie Honegger, and Guido Capitani
- Subjects
Stereochemistry ,Molecular Sequence Data ,Antibody Affinity ,Immunoglobulin Variable Region ,Sequence alignment ,Peptide ,Antigen-Antibody Complex ,medicine.disease_cause ,law.invention ,Mice ,chemistry.chemical_compound ,X-Ray Diffraction ,Affinity chromatography ,Antibody Specificity ,Structural Biology ,law ,Escherichia coli ,medicine ,Animals ,Histidine ,Amino Acid Sequence ,Polyhistidine-tag ,Immunoglobulin Fragments ,Molecular Biology ,Peptide sequence ,Sequence Tagged Sites ,chemistry.chemical_classification ,Antibodies, Monoclonal ,Alkaline Phosphatase ,Recombinant Proteins ,chemistry ,Biochemistry ,Mutation ,Recombinant DNA ,Crystallization ,Sequence Alignment - Abstract
The crystal structure of a mutant form of the single-chain fragment (scFv), derived from the monoclonal anti-His tag antibody 3D5, in complex with a hexahistidine peptide has been determined at 2.7 A resolution. The peptide binds to a deep pocket formed at the interface of the variable domains of the light and the heavy chain, mainly through hydrophobic interaction to aromatic residues and hydrogen bonds to acidic residues. The antibody recognizes the C-terminal carboxylate group of the peptide as well as the main chain of the last four residues and the last three imidazole side-chains. The crystals have a solvent content of 77% (v/v) and form 70 A-wide channels that would allow the diffusion of peptides or even small proteins. The anti-His scFv crystals could thus act as a framework for the crystallization of His-tagged target proteins. Designed mutations in framework regions of the scFv lead to high-level expression of soluble protein in the periplasm of Escherichia coli. The recombinant anti-His scFv is a convenient detection tool when fused to alkaline phosphatase. When immobilized on a matrix, the antibody can be used for affinity purification of recombinant proteins carrying a very short tag of just three histidine residues, suitable for crystallization. The experimental structure is now the basis for the design of antibodies with even higher stability and affinity.
- Published
- 2002
18. A pathway for repair of NAD(P)H in plants
- Author
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Maite Colinas, Michael Moulin, Markus Kaufmann, Holly V. Shaw, Sylvain Loubéry, and Teresa B. Fitzpatrick
- Subjects
0106 biological sciences ,Models, Molecular ,Metabolite ,Arabidopsis ,Sequence Homology ,Plant Biology ,Arabidopsis/genetics/metabolism ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Models ,Gene Expression Regulation, Plant ,Plastids ,Plastids/metabolism ,chemistry.chemical_classification ,Microscopy ,0303 health sciences ,Racemases and Epimerases/chemistry/genetics/metabolism ,Microscopy, Confocal ,biology ,Molecular Structure ,Blotting ,Reverse Transcriptase Polymerase Chain Reaction ,Metabolic Networks and Pathways/genetics ,food and beverages ,Plants ,Plants, Genetically Modified ,Mitochondria ,Amino Acid ,ddc:580 ,Confocal ,Western ,Metabolic Networks and Pathways ,Protein Structure ,NADP/chemistry/metabolism ,Blotting, Western ,Molecular Sequence Data ,Racemases and Epimerases ,Genetically Modified ,Cofactor ,03 medical and health sciences ,Mitochondria/metabolism ,Luminescent Proteins/genetics/metabolism ,Amino Acid Sequence ,Molecular Biology ,Hydro-Lyases ,030304 developmental biology ,Hydro-Lyases/chemistry/genetics/metabolism ,Arabidopsis Proteins/chemistry/genetics/metabolism ,Sequence Homology, Amino Acid ,Arabidopsis Proteins ,fungi ,Molecular ,Plant ,Cell Biology ,Metabolism ,NAD ,Salvage enzyme ,Protein Structure, Tertiary ,Luminescent Proteins ,Glycerol-3-phosphate dehydrogenase ,Enzyme ,Gene Expression Regulation ,chemistry ,Dehydratase ,Mutation ,biology.protein ,NAD+ kinase ,Tertiary ,NADP ,NAD/chemistry/metabolism ,010606 plant biology & botany - Abstract
Unwanted enzyme side reactions and spontaneous decomposition of metabolites can lead to a build-up of compounds that compete with natural enzyme substrates and must be dealt with for efficient metabolism. It has recently been realized that there are enzymes that process such compounds, formulating the concept of metabolite repair. NADH and NADPH are vital cellular redox cofactors but can form non-functional hydrates (named NAD(P)HX) spontaneously or enzymatically that compete with enzymes dependent on NAD(P)H, impairing normal enzyme function. Here we report on the functional characterization of components of a potential NAD(P)H repair pathway in plants comprising a stereospecific dehydratase (NNRD) and an epimerase (NNRE), the latter being fused to a vitamin B6 salvage enzyme. Through the use of the recombinant proteins, we show that the ATP-dependent NNRD and NNRE act concomitantly to restore NAD(P)HX to NAD(P)H. NNRD behaves as a tetramer and NNRE as a dimer, but the proteins do not physically interact. In vivo fluorescence analysis demonstrates that the proteins are localized to mitochondria and/or plastids, implicating these as the key organelles where this repair is required. Expression analysis indicates that whereas NNRE is present ubiquitously, NNRD is restricted to seeds but appears to be dispensable during the normal Arabidopsis life cycle.
- Published
- 2014
19. The pseudoenzyme PDX1.2 boosts vitamin B6 biosynthesis under heat and oxidative stress in Arabidopsis
- Author
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Pedro Surriabre, Svetlana Boycheva, Markus Kaufmann, Marina Tambasco-Studart, Teresa B. Fitzpatrick, Cyril Moccand, and Maja Raschke
- Subjects
Models, Molecular ,Hot Temperature ,endocrine system diseases ,Nitrogenous Group Transferases ,Regulator ,Arabidopsis ,Arabidopsis/genetics/physiology ,medicine.disease_cause ,Biochemistry ,Antioxidants ,Biosynthesis ,Enzyme Catalysis ,Plant Biochemistry ,Pyridoxal Phosphate ,Stress Response ,chemistry.chemical_compound ,Models ,Pyridoxal phosphate ,Gene knockdown ,biology ,food and beverages ,ddc:580 ,Gene Knockdown Techniques ,Vitamin ,endocrine system ,Physiological ,Molecular Sequence Data ,Vitamin B 6/metabolism ,Nitrogenous Group Transferases/chemistry/genetics/metabolism ,Stress ,digestive system ,Cofactor ,Stress, Physiological ,Carbon-Nitrogen Lyases ,medicine ,Amino Acid Sequence ,Molecular Biology ,Arabidopsis Proteins/chemistry/genetics/metabolism ,Arabidopsis Proteins ,Molecular ,Cell Biology ,biology.organism_classification ,Vitamin B 6 ,Oxidative Stress ,chemistry ,biology.protein ,Enzymology ,Oxidative stress - Abstract
Vitamin B6 is an indispensable compound for survival, well known as a cofactor for numerous central metabolic enzymes and more recently for playing a role in several stress responses, particularly in association with oxidative stress. Regulatory aspects for the use of the vitamin in these roles are not known. Here we show that certain plants carry a pseudoenzyme (PDX1.2), which is involved in regulating vitamin B6 biosynthesis de novo under stress conditions. Specifically, we demonstrate that Arabidopsis PDX1.2 enhances the activity of its catalytic paralogs by forming a heterododecameric complex. PDX1.2 is strongly induced by heat as well as singlet oxygen stress, concomitant with an enhancement of vitamin B6 production. Analysis of pdx1.2 knockdown lines demonstrates that boosting vitamin B6 content is dependent on PDX1.2, revealing that this pseudoenzyme acts as a positive regulator of vitamin B6 biosynthesis during such stress conditions in plants., Journal of Biological Chemistry, 289 (12), ISSN:0021-9258, ISSN:1083-351X
- Published
- 2014
20. Wie die Schweiz jetzt Lebensmittelchemiker ausbildet
- Author
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Markus Kaufmann
- Subjects
General Chemical Engineering ,General Chemistry - Abstract
Fuhrungskrafte in der Lebensmittelsicherheit mussen analytisch-methodisch fit sein und sich im internationalen Warenverkehr, bei der Ernahrungspolitik und der Toxikologie gut auskennen. Zudem sollten sie Kompetenzen in Betriebsfuhrung und Offentlichkeitsarbeit mitbringen. In der Schweiz tragt ein neues Ausbildungskonzept fur Lebensmittelchemiker diesen Anspruchen Rechnung.
- Published
- 2010
21. Pharmacological Potentiators of TRPM5 Channel Activity
- Author
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Gul Erdemli, Reinhardt Juergen, Markus Kaufmann, Sandra Siehler, and Igor Dzhura
- Subjects
Chemistry ,Genetics ,Biophysics ,Channel (broadcasting) ,TRPM5 ,Potentiator ,Molecular Biology ,Biochemistry ,Biotechnology - Published
- 2013
22. The crystal structure of the Mycobacterium tuberculosis Rv3019c-Rv3020c ESX complex reveals a domain-swapped heterotetramer
- Author
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Mark A, Arbing, Markus, Kaufmann, Tung, Phan, Sum, Chan, Duilio, Cascio, and David, Eisenberg
- Subjects
Bacterial Proteins ,Genes, Bacterial ,Multigene Family ,Molecular Sequence Data ,Amino Acid Sequence ,Mycobacterium tuberculosis ,Protein Multimerization ,Crystallography, X-Ray ,Sequence Alignment ,Article ,Protein Structure, Tertiary - Abstract
Mycobacterium tuberculosis encodes five gene clusters (ESX-1 to ESX-5) for Type VII protein secretion systems that are implicated in mycobacterial pathogenicity. Substrates for the secretion apparatus are encoded within the gene clusters and in additional loci that lack the components of the secretion apparatus. The best characterized substrates are the ESX complexes, 1:1 heterodimers of ESAT-6 and CFP-10, the prototypical member that has been shown to be essential for Mycobacterium tuberculosis pathogenesis. We have determined the structure of EsxRS, a homolog of EsxGH of the ESX-3 gene cluster, at 1.91 Å resolution. The EsxRS structure is composed of two four-helix bundles resulting from the 3D domain swapping of the C-terminal domain of EsxS, the CFP-10 homolog. The four-helix bundles at the extremities of the complex have a similar architecture to the structure of ESAT-6·CFP-10 (EsxAB) of ESX-1, but in EsxRS a hinge loop linking the α-helical domains of EsxS undergoes a loop-to-helix transition that creates the domain swapped EsxRS tetramer. Based on the atomic structure of EsxRS and existing biochemical data on ESX complexes, we propose that higher order ESX oligomers may increase avidity of ESX binding to host receptor molecules or, alternatively, the conformational change that creates the domain swapped structure may be the basis of ESX complex dissociation that would free ESAT-6 to exert a cytotoxic effect.
- Published
- 2010
23. Effects of clonidine and midazolam premedication on bispectral index and recovery after elective surgery
- Author
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A. Paris, Markus Kaufmann, Philipp Renz, Peter H. Tonner, Jens Scholz, Thomas Ledowski, Berthold Bein, and Thees Lemke
- Subjects
Adult ,Male ,Visual analogue scale ,Sedation ,Midazolam ,Premedication ,Administration, Oral ,Placebo ,Clonidine ,Adrenocorticotropic Hormone ,Double-Blind Method ,Heart Rate ,Heart rate ,medicine ,Humans ,Anesthesia ,Postoperative Period ,Prospective Studies ,Pain Measurement ,business.industry ,Middle Aged ,Anesthesiology and Pain Medicine ,Elective Surgical Procedures ,Bispectral index ,medicine.symptom ,business ,Adrenergic alpha-Agonists ,Anesthetics, Intravenous ,medicine.drug - Abstract
BACKGROUND AND OBJECTIVES Alpha-2 agonists offer useful effects that make these drugs an interesting alternative for pharmacological premedication. METHODS In a randomized, double-blind study, effects of clonidine (150 microg orally), midazolam (7.5 mg orally) and placebo administered 60-90 min prior to estimated anaesthesia induction time were investigated in 60 healthy ASA I or II patients. All patients received dipotassiumchlorazepate the evening before surgery. At predefined time points, effects of premedication on bispectral index, sedation score and visual analogue scales for anxiety and pain, cognitive function and stress hormones were determined. RESULTS Administration of low-dose clonidine was associated with slightly lower bispectral index scores than a standard dose of midazolam or placebo. There were no significant differences in sedation score, visual analogue scale for anxiety and pain and cognitive function between treatment regimens. Clonidine, but not midazolam, reduced anaesthetic requirements for induction of anaesthesia and prevented an increase in heart rate as well as an increase in adrenocorticotropic hormone plasma levels during the preoperative period (P < 0.05 vs. placebo). Clonidine administration did not delay postoperative recovery. CONCLUSION Clonidine augmented haemodynamic stability and partially blunted stress responses as determined by adrenocorticotropic hormone plasma levels. In addition, clonidine did not delay postoperative recovery. Therefore, surrogate parameters indicate that preanaesthetic medication with clonidine may be superior to midazolam in healthy individuals. Further studies have to confirm these results with regard to outcome parameters.
- Published
- 2009
24. Dental injuries resulting from tracheal intubation--a retrospective study
- Author
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Jobst Vogel, Gabriel Krastl, Andreas Filippi, Stefan Stübinger, and Markus Kaufmann
- Subjects
Adult ,Male ,Adolescent ,medicine.medical_treatment ,Anesthesia, Dental ,Dentistry ,Crown (dentistry) ,Young Adult ,stomatognathic system ,Risk Factors ,medicine ,Intubation, Intratracheal ,Maxilla ,Intubation ,Humans ,Maxillary central incisor ,Child ,Anterior teeth ,Aged ,Retrospective Studies ,Orthodontics ,Aged, 80 and over ,Tooth Crown ,business.industry ,Tracheal intubation ,Age Factors ,Tooth Injuries ,Retrospective cohort study ,Periodontium ,Middle Aged ,Tooth Avulsion ,Incisor ,stomatognathic diseases ,Child, Preschool ,Regression Analysis ,Female ,Oral Surgery ,business ,Anesthesia, Inhalation - Abstract
Even though it is known that dental injuries may occur in connection with tracheal intubation, the topic has hardly been evaluated in literature so far. Thus, this retrospective study was conducted including the data of 115-151 patients. All patients involved had been exposed to general anesthesia between 1995 and 2005. The resulting tooth injuries were assessed according to the following parameters: age, kind of hospital conducting treatment, intubation difficulties, pre-existing tooth damage, type and localization of tooth, type of tooth damage, and the number of teeth injured. At least 170 teeth were injured in 130 patients, while patients 50 years of age and older were especially affected. In contrast to older patients where in the majority of cases the periodontium (lateral dislocation) was injured, in younger patients dental hard tissue (crown fracture) was more likely to be affected. It was calculated that patients from the cardiothoracic surgery clinic were showing the highest risk of tooth damage. In more than three-fourth of all cases the anterior teeth of the maxilla, especially the maxillary central incisors, were affected. Pre-existing dental pathology like caries, marginal periodontitis and tooth restorations were often distinguishable prior to operation. Mouthguards in connection with tracheal intubation are not generally recommended as preventive device, due to the already limited amount of space available. Instead, pre-existing risk factors should be thoroughly explored before the induction of intubation narcosis.
- Published
- 2009
25. Detection of 53 novel DNA variations within the tyrosinase gene and accumulation of mutations in 17 patients with albinism
- Author
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Sven, Opitz, Barbara, Käsmann-Kellner, Markus, Kaufmann, Eberhard, Schwinger, and Christine, Zühlke
- Subjects
Polymorphism, Genetic ,Albinism, Oculocutaneous ,Monophenol Monooxygenase ,DNA Mutational Analysis ,Mutation ,Humans ,DNA - Abstract
Oculocutaneous albinism (OCA) in man may be caused by mutations within the tyrosinase gene (TYR) resulting in OCA1. Analysing patients with recessively inherited albinism we found DNA variations in 82 unrelated individuals. 53 out of 78 mutations and polymorphisms revealed by this study are not published previously. The changes include 68 nucleotide substitutions resulting in amino acid changes, stop mutations and polymorphisms as well as four nucleotide insertions and six deletions. Furthermore, we found an accumulation of three to five mutations in 17 patients with OCA1.
- Published
- 2004
26. The glucose transporter of the Escherichia coli phosphotransferase system: linker insertion mutants and split variants
- Author
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Rudolf Beutler, Bernhard Erni, Francesco Ruggiero, and Markus Kaufmann
- Subjects
Models, Molecular ,Cytoplasm ,Monosaccharide Transport Proteins ,Operon ,Protein subunit ,Molecular Sequence Data ,Genetic Variation ,PEP group translocation ,Periplasmic space ,Biology ,Biochemistry ,Transmembrane protein ,Peptide Fragments ,Protein Structure, Secondary ,Deoxyribonuclease EcoRI ,Phosphotransferase ,Mutagenesis, Insertional ,Escherichia coli ,Amino Acid Sequence ,Phosphoenolpyruvate Sugar Phosphotransferase System ,Peptide sequence ,Linker ,Plasmids - Abstract
The IICB(Glc) subunit of the glucose transporter acts by a mechanism which couples vectorial translocation with phosphorylation of the substrate. It contains 8 transmembrane segments connected by 4 periplasmic, 2 short, 1 long (80 residues), cytoplasmic loops and an independently folding cytoplasmic domain at the C-terminus. Random DNase I cleavage, EcoRI linker insertion, and screening for transport-active mutants afforded 12 variants with between 46% and 116% of wild-type sugar phosphorylation activity. They carried inserts of up to 29 residues and short deletions in periplasmic loops 1, 2, and 3, in the long cytoplasmic loop 3, and in the linker region between the membrane spanning IIC(Glc) and the cytoplasmic IIB(Glc) domains. Disruption of the gene at the sites of linker insertion decreased the expression level and diminished phosphotransferase activity to between 7% and 32%. IICB(Glc) with a discontinuity in the cytoplasmic loop was purified to homogeneity as a stable complex. It was active only if encoded by a dicistronic operon but not if encoded by two genes on two different replicons, suggesting that spatial proximity of the nascent polypeptide chains is important for folding and membrane assembly.
- Published
- 2000
27. Detection of 53 novel DNA variations within the tyrosinase gene and accumulation of mutations in 17 patients with albinism
- Author
-
Barbara Käsmann-Kellner, Eberhard Schwinger, Markus Kaufmann, Christine Zühlke, and Sven Opitz
- Subjects
Genetics ,chemistry.chemical_classification ,Tyrosinase ,Biology ,medicine.disease ,Oculocutaneous albinism ,Molecular biology ,Amino acid ,chemistry.chemical_compound ,chemistry ,Albinism ,medicine ,Nucleotide ,Gene ,Genetics (clinical) ,DNA - Abstract
Oculocutaneous albinism (OCA) in man may be caused by mutations within the tyrosinase gene (TYR) resulting in OCA1. Analysing patients with recessively inherited albinism we found DNA variations in 82 unrelated individuals. 53 out of 78 mutations and polymorphisms revealed by this study are not published previously. The changes include 68 nucleotide substitutions resulting in amino acid changes, stop mutations and polymorphisms as well as four nucleotide insertions and six deletions. Furthermore, we found an accumulation of three to five mutations in 17 patients with OCA1. © 2004 Wiley-Liss, Inc.
- Published
- 2004
28. It takes two to tango: defining an essential second active site in pyridoxal 5'-phosphate synthase
- Author
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Cyril Moccand, Thérésa Bridget Fitzpatrick, and Markus Kaufmann
- Subjects
Coenzyme ,lcsh:Medicine ,Glutaminase activity ,Biochemistry ,chemistry.chemical_compound ,Glyceraldehyde ,Catalytic Domain ,Pyridoxal phosphate ,lcsh:Science ,0303 health sciences ,Multidisciplinary ,030302 biochemistry & molecular biology ,Glyceraldehyde 3-Phosphate/metabolism ,Enzymes ,ddc:580 ,Ribosemonophosphates/metabolism ,Pyridoxal Phosphate ,Ribosemonophosphates ,Metabolic Networks and Pathways ,Research Article ,Protein Binding ,Transaminases/chemistry ,Biology ,Protein Chemistry ,Glyceraldehyde 3-Phosphate ,Enzyme Regulation ,03 medical and health sciences ,Glutaminase ,Multienzyme Complexes ,Animals ,Humans ,Enzyme kinetics ,Pyridoxal ,Transaminases ,030304 developmental biology ,Glutamine amidotransferase ,Enzyme Kinetics ,Vitamin B 6/biosynthesis ,Cofactors ,lcsh:R ,Active site ,Proteins ,Multienzyme Complexes/chemistry ,Vitamin B 6 ,chemistry ,Enzyme Structure ,biology.protein ,Biocatalysis ,Pyridoxal Phosphate/metabolism ,lcsh:Q ,Glyceraldehyde 3-phosphate - Abstract
The prevalent de novo biosynthetic pathway of vitamin B6 involves only two enzymes (Pdx1 and Pdx2) that form an ornate multisubunit complex functioning as a glutamine amidotransferase. The synthase subunit, Pdx1, utilizes ribose 5-phosphate and glyceraldehyde 3-phosphate, as well as ammonia derived from the glutaminase activity of Pdx2 to directly form the cofactor vitamer, pyridoxal 5′-phosphate. Given the fact that a single enzyme performs the majority of the chemistry behind this reaction, a complicated mechanism is anticipated. Recently, the individual steps along the reaction co-ordinate are beginning to be unraveled. In particular, the binding of the pentose substrate and the first steps of the reaction have been elucidated but it is not known if the latter part of the chemistry, involving the triose sugar, takes place in the same or a disparate site. Here, we demonstrate through the use of enzyme assays, enzyme kinetics, and mutagenesis studies that indeed a second site is involved in binding the triose sugar and moreover, is the location of the final vitamin product, pyridoxal 5′-phosphate. Furthermore, we show that product release is triggered by the presence of a PLP-dependent enzyme. Finally, we provide evidence that a single arginine residue of the C terminus of Pdx1 is responsible for coordinating co-operativity in this elaborate protein machinery.
- Published
- 2011
29. Non-destructive evaluation of an infusion process using capacitive sensing technique
- Author
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Gabriele Chiesura, Markus Kaufmann, Frederick Bossuyt, Thomas Vervust, Yang Yang, Geert Luyckx, Jan Vanfleteren, and Joris Degrieck
- Subjects
Materials science ,Fabrication ,Technology and Engineering ,Polymerization ,Capacitive sensing ,Glass fiber ,technology, industry, and agriculture ,Vitrification ,Wetting ,Composite material ,Capacitance ,Curing (chemistry) - Abstract
In this study, a capacitive sensing based non-destructive evaluation technique is applied to a vacuum assisted resin infusion process for the fabrication of glass fibre reinforced composites, as such different steps of the fabrication process (the injection of resin, the curing and the post curing) can be better understood to increase the quality of the fabricated part and reduce the fabrication costs. An interdigital coplanar capacitive sensor was designed, fabricated, and embedded in the glass fibre reinforced composites. Experimental data clearly shows different stages of the resin infusion process: wetting of the glass fibres marked by rapid increase of capacitance; domination of ionic conduction at the early stage of the cure when the resin is still in a liquid state; the vitrification point, indicating a transition of the resin from a gelly state to a glassy state, marked by the relatively big decrease in capacitance; further polymerization during post-curing, marked by a peak in capacitance at the beginning of post-curing cycle, and finally the completion of the cure marked by the saturation of capacitance to a final value. The different phenomena observed during the experiment can be used as a tool for in situ on-line monitoring of composites cure.
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