Copper is an essential micronutrient, but toxic in excess. Sulfolobus solfataricus cells have the ability to adapt to fluctuations of copper levels in their external environment. To better understand the molecular mechanism behind the organismal response to copper, the expression of the cluster of genes copRTA, which encodes the copper-responsive transcriptional regulator CopR, the copper-binding protein CopT, and CopA, has been investigated and the whole operon has been shown to be cotranscribed at low levels from the copR promoter under all conditions, whereas increased transcription from the copTA promoter occurs in the presence of excess copper. Furthermore, the expression of the copper-transporting ATPase CopA over a 27-h interval has been monitored by quantitative real-time RT-PCR and compared to the pattern of cellular copper accumulation, as determined in a parallel analysis by Inductively Coupled Plasma Optical Emission spectrometry (ICP-OES). The results provide the basis for a model of the molecular mechanisms of copper homeostasis in Sulfolobus, which relies on copper efflux and sequestration.
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http://dx.doi.org/10.1016/j.bbrc.2009.05.013 | DOI Listing |
Org Lett
January 2025
School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China.
An unprecedented synergistic copper- and amine-catalyzed cyclization of enynone is reported. This reaction features an efficient and straightforward construction of multisubstituted tetralone through an amine-assisted regioselective oxygen atom transfer process and stereoselective intramolecular Michael addition cyclization. Under dehydrative reaction conditions, the synthesis of tetrahydronaphthylimine derivatives with ketone group tolerance is achieved, which could be challenging via traditional methods.
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January 2025
Stem Cells Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
Introduction: The development of efficient and sustainable catalytic methodolo-gies has garnered considerable attention in contemporary organic synthesis.
Methods: Herein, we present a novel approach employing the Cu@DPP-SPION catalyst for the synthesis of ethyl 4-(aryl)-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives. This versatile catalytic system incorporates copper nanoparticles supported on 4-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)benzoic acid-functionalized superparamagnetic iron oxide nanoparticles (SPIONs).
Mater Horiz
January 2025
Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Straße 24/25, 14476, Germany.
Two-dimensional transition metal dichalcogenides (2D TMDCs) can be combined with organic semiconductors to form hybrid van der Waals heterostructures. Specially, non-fullerene acceptors (NFAs) stand out due to their excellent absorption and exciton diffusion properties. Here, we couple monolayer tungsten diselenide (ML-WSe) with two well performing NFAs, ITIC, and IT-4F (fluorinated ITIC) to achieve hybrid architectures.
View Article and Find Full Text PDFOrg Lett
January 2025
Gansu International Scientific and Technological Cooperation Base of Water-Retention Chemical Functional Materials, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, China.
Here, we present a three-component successive radical addition strategy for the preparation of complex noncanonical α-amino acids from easily available glycine derivatives, alkenes, and aryl sulfonium salts via a copper-catalyzed photoredox-neutral catalytic cycle. The utility of this method is further demonstrated by its application in late-stage site-selective modifications of glycine residues in short peptides. It is worth noting that only 1 mol % copper catalyst is required in this reaction, demonstrating high catalytic efficiency.
View Article and Find Full Text PDFACS ES T Water
January 2025
Mechanical Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom.
Wet chemical sensors autonomously sample and analyze water using chemical assays. Their internal fluidics are not susceptible to biofouling (the undesirable accumulation of microorganisms, algae, and animals in natural waters) due to the harsh chemical environment and dark conditions; however, the sample intake and filter are potentially susceptible. This paper describes the use of copper intake filters, incorporated to prevent fouling, on two different wet chemical nitrate sensors that each use different variants of the Griess assay (in particular, different nitrate reduction steps) to quantify nitrate concentrations.
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