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971.
Maurer B Mathias U Papatheodorou P Shekfeh S Orth J Jank T Schwan C Sippl W Aktories K Jung M 《Molecular bioSystems》2011,7(3):799-808
ADP-ribosyltransferases (ADP-RTs) use NAD(+) to transfer an ADP-ribosyl group to target proteins. Although some ADP-RTs are bacterial toxins only few inhibitors are known. Here we present the development of fluorescence-based assays and a focussed library screening using kinase inhibitors as a new approach towards inhibitors of ADP-RTs. Different screening setups were established using surrogate small molecule substrates or the quantitation of the cofactor NAD(+). Proof-of-principle screening experiments were performed using a kinase inhibitor library in order to target the NAD(+) binding pockets. This led to the discovery of structurally different lead inhibitors for the mono-ADP-ribosyltransferases Mosquitocidal toxin (MTX) from Bacillus sphaericus SSII-1, C3bot toxin from Clostridium botulinum and CDTa from Clostridium difficile. The interaction of the inhibitors with the toxin proteins was analyzed by means of docking and binding free energy calculations. Binding at the nicotinamide subpocket, which shows a significant difference in the three enzymes, is used to explain the selectivity of the identified inhibitors and offers an opportunity for further development of potent and selective inhibitors. 相似文献
972.
Nowak C Laredo T Gebert J Lipkowski J Gennis RB Ferguson-Miller S Knoll W Naumann RL 《Metallomics : integrated biometal science》2011,3(6):619-627
Potentiometric titrations of the cytochrome c oxidase (CcO) immobilized in a biomimetic membrane system were followed by two-dimensional surface-enhanced IR absorption spectroscopy (2D SEIRAS) in the ATR-mode. Direct electron transfer was employed to vary the redox state of the enzyme. The CcO was shown to undergo a conformational transition from a non-activated to an activated state after it was allowed to turnover in the presence of oxygen. Differences between the non-activated and activated state were revealed by 2D SEIRA spectra recorded as a function of potential. The activated state was characterized by a higher number of correlated transitions as well as a higher number of amino acids associated with electron transfer. 相似文献
973.
Drewitz M Helbling M Fried N Bieri M Moritz W Lichtenberg J Kelm JM 《Biotechnology journal》2011,6(12):1488-1496
Although the relevance of three-dimensional (3-D) culture has been recognized for years and exploited at an academic level, its translation to industrial applications has been slow. The development of reliable high-throughput technologies is clearly a prerequisite for the industrial implementation of 3-D models. In this study the robustness of spherical microtissue production and drug testing in a 96-well hanging-drop multiwell plate format was assessed on a standard 96-well channel robotic platform. Microtissue models derived from six different cell lines were produced and characterized according to their growth profile and morphology displaying high-density tissue-like reformation and growth over at least 15 days. The colon cancer cell line HCT116 was chosen as a model to assess microtissue-based assay reproducibility. Within three individual production batches the size variations of the produced microtissues were below 5%. Reliability of the microtissue-based assay was tested using two reference compounds, staurosporine and chlorambucil. In four independent drug testings the calculated IC(50) values were benchmarked against 2-D multiwell testings displaying similar consistency. The technology presented here for the automated production of a variety of microtissues for efficacy testing in a standard 96-well format will aid the implementation of more organotypic models at an early time point in the drug discovery process. 相似文献
974.
Dorothy Koveal Anderson S. Pinheiro Wolfgang Peti Rebecca Page 《Biomolecular NMR assignments》2011,5(1):39-41
The backbone and side chain resonance assignments of the murine KSR1 CA1 domain have been determined based on triple-resonance
experiments using uniformly [13C, 15N]-labeled protein. This assignment is the first step towards the determination of the three-dimensional structure of the
unique KSR1 CA1 domain. 相似文献
975.
Horničáková M Kohoutová J Schlagnitweit J Wohlschlager C Ettrich R Fiala R Schoefberger W Müller N 《Biomolecular NMR assignments》2011,5(2):169-175
PsbQ is one of the extrinsic proteins situated on the lumenal surface of photosystem II (PSII) in the higher plants and green
algae. Its three-dimensional structure was determined by X-ray crystallography with exception of the residues 14–33. To obtain
further details about its structure and potentially its dynamics, we approached the problem by NMR. In this paper we report
1H, 15N, and 13C NMR assignments for the PsbQ protein. The very challenging oligo-proline stretches could be assigned using 13C-detected NMR experiments that enabled the assignments of twelve out of the thirteen proline residues of PsbQ. The identification
of PsbQ secondary structure elements on the basis of our NMR data was accomplished with the programs TALOS+, web server CS23D
and CS-Rosetta. To obtain additional secondary structure information, three-bond HN-Hα J-coupling constants and deviation of experimental 13Cα and 13Cβ chemical shifts from random coil values were determined. The resulting “consensus” secondary structure of PsbQ compares very
well with the resolved regions of the published X-ray crystallographic structure and gives a first estimate of the structure
of the “missing link” (i.e. residues 14–33), which will serve as the basis for the further investigation of the structure,
dynamics and interactions. 相似文献
976.
It is an established fact that allelic variation and post-translational modifications create different variants of proteins, which are observed as isoelectric and size subspecies in two-dimensional gel based proteomics. Here we explore the stromal proteome of spinach and Arabidopsis chloroplast and show that clustering of mass spectra is a useful tool for investigating such variants and detecting modified peptides with amino acid substitutions or post-translational modifications. This study employs data mining by hierarchical clustering of MALDI-MS spectra, using the web version of the SPECLUST program (http://bioinfo.thep.lu.se/speclust.html). The tool can also be used to remove peaks of contaminating proteins and to improve protein identification, especially for species without a fully sequenced genome. Mutually exclusive peptide peaks within a cluster provide a good starting point for MS/MS investigation of modified peptides, here exemplified by the identification of an A to E substitution that accounts for the isoelectric heterogeneity in protein isoforms. 相似文献
977.
Barjaktarovic Z Schmaltz D Shyla A Azimzadeh O Schulz S Haagen J Dörr W Sarioglu H Schäfer A Atkinson MJ Zischka H Tapio S 《PloS one》2011,6(12):e27811
BACKROUND: Radiation therapy treatment of breast cancer, Hodgkin's disease or childhood cancers expose the heart to high local radiation doses, causing an increased risk of cardiovascular disease in the survivors decades after the treatment. The mechanisms that underlie the radiation damage remain poorly understood so far. Previous data show that impairment of mitochondrial oxidative metabolism is directly linked to the development of cardiovascular disease. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the radiation-induced in vivo effects on cardiac mitochondrial proteome and function were investigated. C57BL/6N mice were exposed to local irradiation of the heart with doses of 0.2 Gy or 2 Gy (X-ray, 200 kV) at the age of eight weeks, the control mice were sham-irradiated. After four weeks the cardiac mitochondria were isolated and tested for proteomic and functional alterations. Two complementary proteomics approaches using both peptide and protein quantification strategies showed radiation-induced deregulation of 25 proteins in total. Three main biological categories were affected: the oxidative phophorylation, the pyruvate metabolism, and the cytoskeletal structure. The mitochondria exposed to high-dose irradiation showed functional impairment reflected as partial deactivation of Complex I (32%) and Complex III (11%), decreased succinate-driven respiratory capacity (13%), increased level of reactive oxygen species and enhanced oxidation of mitochondrial proteins. The changes in the pyruvate metabolism and structural proteins were seen with both low and high radiation doses. CONCLUSION/SIGNIFICANCE: This is the first study showing the biological alterations in the murine heart mitochondria several weeks after the exposure to low- and high-dose of ionizing radiation. Our results show that doses, equivalent to a single dose in radiotherapy, cause long-lasting changes in mitochondrial oxidative metabolism and mitochondria-associated cytoskeleton. This prompts us to propose that these first pathological changes lead to an increased risk of cardiovascular disease after radiation exposure. 相似文献
978.
979.
The present study evaluated two previously developed methods for amplification of bovine mtDNA segments of 109 and 271 base pairs (bp) by real-time polymerase chain reaction (PCR). Beef samples were sterilised experimentally at different temperatures (126 degrees C, 129 degrees C, 132 degrees C and 135 degrees C). These experimentally sterilised beef samples and nine commercial meat and bone meals (MBM) were mixed to a reference plant concentrate in strengths of 50%, 10%, 5%, and 1%. The results of the following PCR showed that the Bos-109 real-time PCR assay was able to detect all the experimental beef samples with exception of the mixtures of beef heated experimentally to 135 degrees C. In mixtures of industrial MBM bovine DNA were always found. Comparatively, the beef sterilised at 135 degrees C and 132 degrees C (and their respective mixtures) and the mixture containing 1% of beef sterilised at 129 degrees C were not detectable with the PCR assay amplifying a target of 271 bp. Using this PCR mixtures of industrial MBM were only weakly detected. The low concentrated mixtures of the extremely processed MBM-1 and MBM-2 even reported negative. These results indicate that the detectability of bovine DNA is strongly influenced by the degree of the thermal treatment. Only the PCR assay amplifying relatively short fragments of a multi-copy mitochondrial target was reliable for the detection of correctly heated MBM in mixed feed. 相似文献
980.
Maurizio Scarpa Zsuzsanna Almássy Michael Beck Olaf Bodamer Iain A Bruce Linda De Meirleir Nathalie Guffon Encarna Guillén-Navarro Pauline Hensman Simon Jones Wolfgang Kamin Christoph Kampmann Christina Lampe Christine A Lavery Elisa Leão Teles Bianca Link Allan M Lund Gunilla Malm Susanne Pitz Michael Rothera Catherine Stewart Anna Tylki-Szymańska Ans van der Ploeg Robert Walker Jiri Zeman James E Wraith 《Orphanet journal of rare diseases》2011,6(1):1-18