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101.
102.
Dr. Bettina Sommer Dr. Holger von Moeller Martina Haack Dr. Farah Qoura Clemens Langner Dr. Gleb Bourenkov Dr. Daniel Garbe Dr. Bernhard Loll Prof. Dr. Thomas Brück 《Chembiochem : a European journal of chemical biology》2015,16(1):110-118
Isobutanol is deemed to be a next‐generation biofuel and a renewable platform chemical. 1 Non‐natural biosynthetic pathways for isobutanol production have been implemented in cell‐based and in vitro systems with Bacillus subtilis acetolactate synthase (AlsS) as key biocatalyst. 2 – 6 AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg2+ as cofactors. AlsS also catalyzes the conversion of 2‐ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol. Our phylogenetic analysis suggests that the ALS enzyme family forms a distinct subgroup of ThDP‐dependent enzymes. To unravel catalytically relevant structure‐function relationships, we solved the AlsS crystal structure at 2.3 Å in the presence of ThDP, Mg2+ and in a transition state with a 2‐lactyl moiety bound to ThDP. We supplemented our structural data by point mutations in the active site to identify catalytically important residues. 相似文献
103.
Changes in actin and tubulin expression in osteogenic cells cultured on bioactive glass‐based surfaces
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Carolina Scanavez Martins Emanuela Prado Ferraz Larissa Moreira Spinola De Castro‐Raucci Lucas Novaes Teixeira William Marcatti Amarú Maximiano Adalberto Luiz Rosa Paulo Tambasco De Oliveira 《Microscopy research and technique》2015,78(11):1046-1053
The present study evaluated whether the changes in the labeling pattern of cytoskeletal proteins in osteogenic cells cultured on bioactive glass‐based materials are due to altered mRNA and protein levels. Primary rat‐derived osteogenic cells were plated on Bioglass® 45S5, Biosilicate®, and borosilicate (bioinert control). The following parameters were assayed: (i) qualitative epifluorescence analysis of actin and tubulin; (ii) quantitative mRNA and protein expression for actin and tubulin by real‐time PCR and ELISA, respectively, and (iii) qualitative analysis of cell morphology by scanning electron microscopy (SEM). At days 3 and 7, the cells grown on borosilicate showed typical actin and tubulin labeling patterns, whereas those on the bioactive materials showed roundish areas devoid of fluorescence signals. The cultures grown on bioactive materials showed significant changes in actin and tubulin mRNA expression that were not reflected in the corresponding protein levels. A positive correlation between the mRNA and protein as well as an association between epifluorescence imaging and quantitative data were only detected for the borosilicate. SEM imaging of the cultures on the bioactive surfaces revealed cells partly or totally coated with material aggregates, whose characteristics resembled the substrate topography. The culturing of osteogenic cells on Bioglass® 45S5 and Biosilicate® affect actin and tubulin mRNA expression but not the corresponding protein levels. Changes in the labeling pattern of these proteins should then be attributed, at least in part, to the presence of a physical barrier on the cell surface as a result of the material surface reactions, thus limiting fluorescence signals. Microsc. Res. Tech. 78:1046–1053, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
104.
Díaz MD Palomino-Schätzlein M Corzana F Andreu C Carbajo RJ del Olmo M Canales-Mayordomo A Pineda-Lucena A Asensio G Jiménez-Barbero J 《Chembiochem : a European journal of chemical biology》2010,11(17):2424-2432
The conformations of two synthetic pentapeptides with antimicrobial activity and their 4-fluorophenylalanine (Pff)-containing analogues (ArXArXAr-NH(2); Ar=Phe, Pff; X=Lys, Arg) have been studied. NMR experiments carried out both in aqueous fluoroalcohol solutions and SDS micelles permitted their interactions with membrane-like environments to be explored. WaterLOGSY experiments and Mn(2+)-based paramagnetic probes were also applied to assess their orientations with respect to the SDS micelles. In addition, pulse-field gradient (PFG) diffusion NMR spectroscopy studies were conducted, under different experimental conditions (i.e., concentration, temperature) to characterize the possible changes in the peptides' aggregation states as a putative critical factor for their antimicrobial activity. Finally, molecular dynamics simulations on a variety of conformations showed the intrinsic flexibility of these peptides in both aqueous solutions and membrane-mimetic systems. 相似文献
105.
Martina Baeumler Frank Gütle Vladimir Polyakov Markus Cäsar Michael Dammann Helmer Konstanzer Wilfried Pletschen Wolfgang Bronner Rüdiger Quay Patrick Waltereit Michael Mikulla Oliver Ambacher Franck Bourgeois Reza Behtash Klaus J. Riepe Paul J. van der Wel Jos Klappe Thomas Rödle 《Journal of Electronic Materials》2010,39(6):756-760
106.
Martina Gensini Dr. Maria Altamura Dr. Tula Dimoulas Dr. Valentina Fedi Dr. Danilo Giannotti Dr. Sandro Giuliani Dr. Antonio Guidi Dr. Nicholas J. S. Harmat Dr. Stefania Meini Dr. Rossano Nannicini Franco Pasqui Manuela Tramontana Dr. Antonio Triolo Dr. Carlo Alberto Maggi Dr. 《ChemMedChem》2010,5(1):65-78
Herein we describe the synthesis of a series of new potent tachykinin NK2 receptor antagonists by the modulation of the C‐ and N‐terminal moieties of ibodutant (MEN 15596, 1 ). The N‐terminal benzo[b]thiophene ring was replaced by different substituted naphthalenes and benzofurans, while further modifications were evaluated at the C‐terminal tetrahydropyran moiety. Most compounds demonstrated a high affinity for the human NK2 receptor and high in vitro antagonist potency, indicating that a wide range of substituents at both termini can be incorporated in the molecule without detrimental effects on the interactions with the NK2 receptor. Selected compounds were tested in vivo confirming their activity as NK2 antagonists. In particular, after both iv and id administration to guinea pig, compound 61 b was able to antagonize NK2‐induced colonic contractions with a potency and duration‐of‐action fully comparable to the reference compound 1 (MEN 15596, ibodutant). 相似文献
107.
Martina Rejtharová Libor Rejthar Katarína Čačková 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2018,35(2):233-240
A sensitive and robust confirmatory method for determination of steroid esters in blood serum is essential for reliable monitoring of possible illegal use of steroid hormones as growth promoters in meat production. A previously used sample preparation methodology was improved. The procedure consists of protein precipitation and removal of phospholipids by dispersive SPE Supel? QuE Z-Sep (Sigma-Aldrich) followed by clean-up on alumina column and LC-MS/MS measurement. The modified method has been validated according to Commission Decision 2002/657/EC. Validation parameters for determination of six testosterone esters and five nortestosterone esters in bovine and porcine blood serum are presented in this article. Decision limits for all analytes were observed in the range 10–20 pg mL?1. The method described is considerably robust for bovine and porcine serum analyses and can be applied both for screening and confirmatory determination in routine residue monitoring. 相似文献
108.
A strategic analysis of the electricity market in Western Australia yields a market potential for renewable energy in Western Australia. However, from a purely financial viewpoint the installation of grid-connected pv-systems still is not economically viable. In this paper a balanced scorecard (BSC) is developed to capture and visualize other than financial benefits. Therefore, the BSC can be used as a marketing tool to communicate the benefits of a privately owned GCPV system to potential customers. 相似文献
109.
Romolo Marcelli Giancarlo Bartolucci George Papaioannu Giorgio De Angelis Andrea Lucibello Emanuela Proietti Benno Margesin Flavio Giacomozzi François Deborgies 《Microsystem Technologies》2010,16(7):1111-1118
The reliability of RF MEMS switches is typically reduced by charging effects occurring in the dielectrics. The aim of this
paper is to discuss these effects, and to propose analytical and equivalent circuit models which account for most of the physical
contributions present in the structure. 相似文献
110.