共查询到20条相似文献,搜索用时 15 毫秒
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Emanuela Berrino Murat Bozdag Sonia Del Prete Fatmah A. S. Alasmary Linah S. Alqahtani Zeid AlOthman 《Journal of enzyme inhibition and medicinal chemistry》2018,33(1):1194-1198
The inhibition of α-, β-, γ-, and δ-class carbonic anhydrases (CAs, EC 4.2.1.1) from bacteria (Vibrio cholerae and Porphyromonas gingivalis) and diatoms (Thalassiosira weissflogii) with a panel of N’-aryl-N-hydroxy-ureas is reported. The α-/β-CAs from V. cholerae (VchCAα and VchCAβ) were effectively inhibited by some of these derivatives, with KIs in the range of 97.5?nM – 7.26?µM and 52.5?nM – 1.81?µM, respectively, whereas the γ-class enzyme VchCAγ was less sensitive to inhibition (KIs of 4.75 – 8.87?µM). The β-CA from the pathogenic bacterium Porphyromonas gingivalis (PgiCAβ) was not inhibited by these compounds (KIs?>?10?µM) whereas the corresponding γ-class enzyme (PgiCAγ) was effectively inhibited (KIs of 59.8?nM – 6.42?µM). The δ-CA from the diatom Thalassiosira weissflogii (TweCAδ) showed effective inhibition with these derivatives (KIs of 33.3?nM – 8.74?µM). As most of these N-hydroxyureas are also ineffective as inhibitors of the human (h) widespread isoforms hCA I and II (KIs?>?10?µM), this class of derivatives may lead to the development of CA inhibitors selective for bacterial/diatom enzymes over their human counterparts and thus to anti-infectives or agents with environmental applications. 相似文献
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Two new adenosine analogs, 2′-(2-bromoethyl) adenosine monophosphate and 3′-(2-bromoethyl) adenosine monophosphate, were synthesized, purified by semipreparative high-pressure liquid chromatography, and completely characterized. A new synthesis of 5′-(2-bromoethyl) adenosine monophosphate is presented which facilitates the preparation of radioactive reagent with label either in the ethyl group or the purine ring of the nucleotide derivative. The reactive moiety of these derivatives, a bromoalkyl group, has the ability to react with the nucleophilic side chains of several amino acids. The second-order, pH-independent rate constants for reaction with the side chains of the amino acids cysteine, lysine, histidine, and tyrosine were determined as 3×10?4, 6×10?6, 3×10?7, and <1×10?7 M?1 sec?1, respectively. These data could be use in estimating the rate enhancement observed in modification of a protein by these affinity-labeling reagents. 5′-(S-(2-hydroxyethyl)cysteine) adenosine monophosphate, the derivative expected from exhaustive digestion of protein in which a cysteinyl residue is modified by 5′-(2-bromoethyl) adenosine monophosphate, and S-2-hydroxyethyl)cysteine, the derivative anticipated upon acid hydrolysis of such a modified protein, were synthesized, characterized, and their elution positions from an amino acid analyzer determined. These bromoethyl AMP derivatives are potential affinity labels for enzymes that bind 2′-, 3′-, or 5′-nucleotides such as TPN, coenzyme A, or ADP, respectively. 相似文献
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Matthias Schaefer 《Basic and Applied Ecology》2009,10(6):582
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《Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences》2000,31(1):213-232
Teleological explanations in evolutionary biology, from Cuvier to the present (and into the future), depend on the metaphor of design for heuristic power and predictive fertility. 相似文献
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Medium chain β-1-alkylglycosides show interesting mild detergent properties. Therefore, their synthesis and purification have been investigated and improved so as to permit preparation of 50–100 g amounts. Preparatory methods are presented for the already known compounds β-1-octyl-, β-1-nonyl and β-1-decyl-glucose and for the new compounds β-1-undecylglucose and β-1-dodecylmaltose. Some relevant properties such as melting point, optical rotation, critical micelle concentration and NMR-spectra have been determined. They illustrate the suitability of this class of detergents for membrane research. 相似文献
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J. Tomasz 《Nucleosides, nucleotides & nucleic acids》2013,32(1):51-61
Abstract A simple procedure is described for the preparation of the title compounds 1, 8 and 9. 3′-3′ or 3′-5′ or 5′-5′ TpT was reacted with a twofold molar excess of TPS in anhydrous DMF, at room temperature, for 5 min, followed by a 1 min in situ treatment of the reaction mixture with excess 7.0 N NH4OH, at 0°C. The alkaline hydrolysis of 1, 8 and 9 proceeds without the assistance of 3′- and 5′-hydroxyl groups resulting in equimolar mixtures of thymidine (4) and thymidine 3′-phosphoramidate (6) (for the 3′-3′ isomer) or thymidine 5′-phosphoramidate (7) (for the 5′-5′ isomer) or 6 and 7 in equal quantities (for the 3′-5′ isomer). 相似文献
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Jack A Gilbert Gregory J. Dick Bethany Jenkins John Heidelberg Eric Allen Katherine R. M. Mackey Edward F. DeLong 《Standards in genomic sciences》2014,9(3):1252-1258
The National Science Foundation’s EarthCube End User Workshop was held at USC Wrigley Marine Science Center on Catalina Island, California in August 2013. The workshop was designed to explore and characterize the needs and tools available to the community that is focusing on microbial and physical oceanography research with a particular emphasis on ‘omic research. The assembled researchers outlined the existing concerns regarding the vast data resources that are being generated, and how we will deal with these resources as their volume and diversity increases. Particular attention was focused on the tools for handling and analyzing the existing data, on the need for the construction and curation of diverse federated databases, as well as development of shared, interoperable, “big-data capable” analytical tools. The key outputs from this workshop include (i) critical scientific challenges and cyber infrastructure constraints, (ii) the current and future ocean ‘omics science grand challenges and questions, and (iii) data management, analytical and associated and cyber-infrastructure capabilities required to meet critical current and future scientific challenges. The main thrust of the meeting and the outcome of this report is a definition of the ‘omics tools, technologies and infrastructures that facilitate continued advance in ocean science biology, marine biogeochemistry, and biological oceanography. 相似文献
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Sucrose, sucrosyl oligosaccharides, and oxidative stress: scavenging and salvaging? 总被引:2,自引:0,他引:2
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In nature, no single plant completes its life cycle withoutencountering environmental stress. When plant cells surpassstress threshold stimuli, chemically reactive oxygen species(ROS) are generated that can cause oxidative damage or act assignals. Plants have developed numerous ROS-scavenging systemsto minimize the cytotoxic effects of ROS. The role of sucrosyloligosaccharides (SOS), including fructans and the raffinosefamily oligosaccharides (RFOs), is well established during stressphysiology. They are believed to act as important membrane protectorsin planta. So far a putative role for sucrose and SOS duringoxidative stress has largely been neglected, as has the contributionof the vacuolar compartment. Recent studies suggest a link betweenSOS and oxidative defence and/or scavenging. SOS might be involvedin stabilizing membrane-associated peroxidases and NADPH oxidases,and SOS-derived radicals might fulfil an intermediate role inoxido-reduction reactions taking place in the vicinity of membranes.Here, these emerging features are discussed and perspectivesfor future research are provided. Key words: Fructan, oxidative stress, raffinose, ROS, sucrose, sucrosyl oligosaccharides
Received 25 September 2008; Revised 20 October 2008 Accepted 23 October 2008 相似文献
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Elizabeth A. Slee Mary T. Harte Ruth M. Kluck Beni B. Wolf Carlos A. Casiano Donald D. Newmeyer Hong-Gang Wang John C. Reed Donald W. Nicholson Emad S. Alnemri Douglas R. Green Seamus J. Martin 《The Journal of cell biology》1999,144(2):281-292
Exit of cytochrome c from mitochondria into the cytosol has been implicated as an important step in apoptosis. In the cytosol, cytochrome c binds to the CED-4 homologue, Apaf-1, thereby triggering Apaf-1–mediated activation of caspase-9. Caspase-9 is thought to propagate the death signal by triggering other caspase activation events, the details of which remain obscure. Here, we report that six additional caspases (caspases-2, -3, -6, -7, -8, and -10) are processed in cell-free extracts in response to cytochrome c, and that three others (caspases-1, -4, and -5) failed to be activated under the same conditions. In vitro association assays confirmed that caspase-9 selectively bound to Apaf-1, whereas caspases-1, -2, -3, -6, -7, -8, and -10 did not. Depletion of caspase-9 from cell extracts abrogated cytochrome c–inducible activation of caspases-2, -3, -6, -7, -8, and -10, suggesting that caspase-9 is required for all of these downstream caspase activation events. Immunodepletion of caspases-3, -6, and -7 from cell extracts enabled us to order the sequence of caspase activation events downstream of caspase-9 and reveal the presence of a branched caspase cascade. Caspase-3 is required for the activation of four other caspases (-2, -6, -8, and -10) in this pathway and also participates in a feedback amplification loop involving caspase-9. 相似文献