排序方式: 共有53条查询结果,搜索用时 951 毫秒
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Dr. Kalani Kariyawasam Dr. Thibault Di Meo Dr. Fabien Hammerer Dr. Marie Valerio-Lepiniec Dr. Giuseppe Sciortino Prof. Jean-Didier Maréchal Prof. Philippe Minard Prof. Jean-Pierre Mahy Dr. Agathe Urvoas Dr. Rémy Ricoux 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(65):14929-14937
A novel inducible artificial metalloenzyme obtained by covalent attachment of a manganese(III)-tetraphenylporphyrin (MnTPP) to the artificial bidomain repeat protein, (A3A3′)Y26C, is reported. The protein is part of the αRep family. The biohybrid was fully characterized by MALDI-ToF mass spectrometry, circular dichroism and UV/Vis spectroscopies. The peroxidase and monooxygenase activities were evaluated on the original and modified scaffolds including those that have a) an additional imidazole, b) a specific αRep bA3-2 that is known to induce the opening of the (A3A3′) interdomain region and c) a derivative of the αRep bA3-2 inducer extended with a His6-Tag (His6-bA3-2). Catalytic profiles are highly dependent on the presence of co-catalysts with the best activity obtained with His6-bA3-2. The entire mechanism was rationalized by an integrative molecular modeling study that includes protein–ligand docking and large-scale molecular dynamics. This constitutes the first example of an entirely artificial metalloenzyme with inducible peroxidase and monooxygenase activities, reminiscent of allosteric regulation of natural enzymatic pathways. 相似文献
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Jean-Yves Dauxois Agathe Guilloux Syed N.U.A. Kirmani 《Comptes Rendus Mathematique》2003,337(11):745-748
Consider a population of individuals who experience two causes of death. We observe the ones alive at time t0 and follow them until death. Given this length bias sample, we propose an estimator of the survival function of ‘initial survival times’ (i.e., for the entire population) under the assumption of proportional hazards for the two causes of death. The large sample behaviour of our estimator is also studied. To cite this article: J.-Y. Dauxois et al., C. R. Acad. Sci. Paris, Ser. I 337 (2003). 相似文献
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Agathe Fanost Laurence de Viguerie Guylaine Ducouret Guillaume Mriguet Philippe Walter Helen Glanville Anne-Laure Rollet Maguy Jaber 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2022,134(1):e202112108
Egg-tempera painting is a pictorial technique widely used in the Middle Ages, although poorly studied in its physico-chemical aspects until now. Here we show how NMR relaxometry and rheology can be combined to probe egg-tempera paints and shed new light on their structure and behavior. Based on recipes of the 15th century, model formulations with egg yolk and green earth have been reproduced to characterize the physicochemical properties of this paint at the mesoscopic and macroscopic scales. The rheological measurements highlight a synergetic effect between green earth and egg yolk, induced by the interactions between them and the structural organisation of the system. 1H NMR relaxometry emphasizes the presence and the structure of a network formed by the yolk and the pigment. 相似文献
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Agathe Paitier Naoufel Haddour Chantal Gondran Timothy M. Vogel 《Molecules (Basel, Switzerland)》2022,27(7)
Low electrical conductivity of carbon materials is a source of potential loss for large carbonaceous electrode surfaces of MFCs due to the long distance traveled by electrons to the collector. In this paper, different configurations of titanium current collectors were used to connect large surfaces of carbon cloth anodes. The current collectors had different distances and contact areas to the anode. For the same anode surface (490 cm2), increasing the contact area from 28 cm2 to 70 cm2 enhanced power output from 58 mW·m−2 to 107 mW·m−2. For the same contact area (28 cm2), decreasing the maximal distance of current collectors to anodes from 16.5 cm to 7.75 cm slightly increased power output from 50 mW·m−2 to 58 mW·m−2. Molecular biology characterization (qPCR and 16S rRNA gene sequencing) of anodic bacterial communities indicated that the Geobacter number was not correlated with power. Moreover, Geobacter and Desulfuromonas abundance increased with the drop in potential on the anode and with the presence of fermentative microorganisms. Electrochemical impedance spectroscopy (EIS) showed that biofilm resistance decreased with the abundance of electroactive bacteria. All these results showed that the electrical gradient arising from collectors shapes microbial communities. Consequently, current collectors influence the performance of carbon-based anodes for full-scale MFC applications. 相似文献
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We prove that, given a countable groupG, the set of countable structures (for a suitable languageL)U
G
whose automorphism group is isomorphic toG is a complete coanalytic set and ifG ≄H thenU
G
is Borel inseparable fromU
H
. We give also a model theoretic interpretation of this result. We prove, in contrast, that the set of countable structures
forL whose automorphism group is isomorphic to ℤ
p
ℕ
,p a prime number, is Π
1
1
&σ
1
1
-complete. 相似文献
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Urvoas A Amekraz B Moulin C Le Clainche L Stöcklin R Moutiez M 《Rapid communications in mass spectrometry : RCM》2003,17(16):1889-1896
Metallochaperones are soluble proteins involved in metal transport and regulation in vivo. Copper metallochaperones belong to a structural family of metal binding domains displaying a ferredoxin-like fold (betaalphabetabetaalphabeta) and a consensus metal-binding motif MXCXXC. The metal-binding selectivities for this class of proteins are poorly documented so far. The present study focuses on the measurement of the selectivity of the copper metallochaperone CopZ from Enterococcus hirae for different metal ions using an experimental approach based on electrospray ionization mass spectrometry (ESI-MS). All the metal cations tested, i.e. Cu(I), Cu(II), Hg(II), Cd(II) and Co(II), form specific metal complexes with CopZ. The study of a chemically modified CopZ as well as variants of CopZ in the active site demonstrated that the complexes observed by ESI-MS, i.e. in the gas phase, corresponded to the complexes previously observed by other analytical methods in solution. Competition experiments allowed the classification of the metal ions by increasing affinities for CopZ as follows: Co < Cd < Hg < Cu. A dissociation constant in the range of 20 microM was determined for cobalt. The affinity of CopZ for the other metals tested was found to be higher, with dissociation constants smaller than micromolar. 相似文献
49.
Let ?R be the preorder of embeddability between countable linear orders colored with elements of Rado's partial order (a standard example of a wqo which is not a bqo). We show that ?R has fairly high complexity with respect to Borel reducibility (e.g. if P is a Borel preorder, then P ≤B ?R), although its exact classification remains open. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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