A tetranuclear mixed ligand copper(II) complex of a pyrazole containing Schiff base and a hydroxyhexahydropyrimidylpyrazole and copper(II) and nickel(II) complexes of the Schiff base having N-donor atoms have been investigated. A 2 equiv amount of 5-methyl-3-formylpyrazole (MPA) and 2 equiv of 1,3-diamino-2-propanol (1,3-DAP) on reaction with 1 equiv of copper(II) nitrate produce an unusual tet...

Introduction Copper is an essential cofactor for several enzymes that catalyse many biochemical reactions crucial for normal cell physiology. Its ability to accept and donate single electrons as it changes oxidation state between Cu+ and Cu2+—that is, Cu(I) and Cu(II), respectively— makes copper an ideal biological cofactor; however, this ability also allows it to readily catalyse the formation...

A fluorescence turn-on probe for Cu(2+) based on the novel copper-mediated dihydrorosamine oxidation reaction has been constructed and employed in the detection of Cu(2+) in water, new born calf serum, and living cells, and the new copper-mediated dihydrorosamine oxidation reaction likely proceeds by a copper redox mechanism.

The two opposing yeast copper regulators, Ace1 and Mac1, were converted into two fluorescent probes, Ace1-FRET and Mac1-FRET, which selectively and sensitively respond to Cu(+). The Cu(+)-binding curves obtained for both regulators as well as for the copper storage proteins Cup1 and Crs5 show that free copper(i) is maintained in a narrow window inside yeast.

Copper isotopic composition is altered in cancerous compared to healthy tissues. However, the rationale for this difference is yet unknown. As a model of Cu isotopic fractionation, we monitored Cu uptake in Saccharomyces cerevisiae, whose Cu import is similar to human. Wild type cells are enriched in 63Cu relative to 65Cu. Likewise, 63Cu isotope enrichment in cells without high-affinity Cu tran...

The trace element copper (Cu) is essential for cell growth. In this report we describe the identification of a new component of the high-affinity Cu transport machinery in yeast, encoded by the CTR3 gene. Ctr3p is a small intracellular cysteine-rich integral membrane protein that restores high-affinity Cu uptake, Cu, Zn superoxide dismutase activity, ferrous iron transport, and respiratory prof...

The N-terminal metal binding extension of the Cu,Zn superoxide dismutase from Haemophilus ducreyi is constituted by a histidine-rich region followed by a methione-rich sequence which shows high similarity with protein motifs involved in the binding of Cu(I). X-ray absorption spectroscopy experiments selectively carried out with peptides corresponding to the two metal binding regions indicate th...

Herein, we report a facile two-step approach to produce gold-incorporated copper (Cu/Au) nanostructures through controlled disproportionation of the Cu(+)-oleylamine complex at 220 °C to form copper nanowires and the subsequent reaction with Au(3+) at different temperatures of 140, 220 and 300 °C. In comparison with copper nanowires, these bimetallic Cu/Au nanostructures exhibit their synergist...

Structure-activity relationships of a nanostructured Cu/ZrO2 catalyst for the steam reforming of methanol (MSR) were investigated under reaction conditions by in situ X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) combined with on-line mass spectrometry (MS). Temperature programmed activation by reduction in hydrogen or by reduction in a mixture of methanol and water (feed) was...

Sulfate-reducing bacterial communities from coastal sediments with a long-term exposure to copper (Cu)-mining residues were studied in lactate enrichments. The toxicity of excess copper may affect sulfate-reducing bacterial communities. Sulfate reduction was monitored by sulfate and organic acid measurements. Molecular diversity was analyzed by 16S rRNA, dissimilatory sulfate reduction dsrAB, a...