Increasing evidence indicates that abnormal Cu2+ binding to Aβ peptides are responsible for the formation of soluble Aβ oligomers and ROS that play essential roles in AD pathogenesis. During studying the Cu2+-chelating treatment of Cu2+-bound Aβ42 aggregates, we found that UV light exposure pronouncedly enhances cytotoxicity of the chelator-treated and -untreated Cu2+-bound Aβ42 aggregates. Thi...

Small-molecule thiols, such as cysteine (CYS) and glutathione (GSH), are essential for maintaining the cellular redox environment and play important roles in regulating various cellular physiological functions. A fluorescence probe (compound 1-Cu2+) for thiols based on coumarin carbohydrazide dinuclear copper complex was developed. Compound 1 was synthesized from the reaction of 7-(diethylamino...

We have measured the extended x-ray absorption-fine-structure (EXAFS) at the Y-K edge of YBa2Cu3Ox for x=6.801, 6.947, 6.968, 6.984 at T=20-300 K. The Y–Cu2 pairs vibrate harmonically but freeze out in the superconducting phase. The Y-O2,3 pairs exhibit strong anharmonicities with a singularity at Tc. With increasing oxygen concentration the Cu2 layer shifts along c towards the Ba layer. Optimu...

We studied the effects of different media for callus induction and differentiation, and pre-culture period of immature wheat embryo culture on biolistic transformation efficiency for including antifreeze gene KN2 and bar conferring resistance to the herbicide bialaphos. The percentage of plantlets generated from induction and differentiation media without Cu2+ was lower than those cultured on d...

We have found that copper(II) ions at about equimolar Cu2+/photosystem II (PS II) reaction center proportions stimulate oxygen evolution nearly twofold. This high affinity Cu-binding site is different from the binding sites of Mn and Ca ions. The analysis of the Cu2+ content in PS II preparations isolated from wild-type tobacco and a tobacco mutant deficient in light-harvesting complex suggests...

A new fluorescent probe P based on rhodamine for Cu2+ was synthesized and characterized. The new probe P showed high selectivity to Cu2+ over other tested metal ions. With optimal conditions, the proposed probe P worked in a wide linear range of 1.0 × 10(-6)-1.0 × 10(-5) M with a detection limit of 3.3 × 10(-7) M Cu2+ in ethanol-water solution (9:1, v:v, 20 mM HEPES, pH 7.0). Furthermore, it ha...

A novel fluorescent Probe 1, based on phenanthro-imidazole has been developed as an efficient chemosensor for the trace detection of copper ions (Cu2+). Probe 1 demonstrated sensitive fluorescence quenching upon binding with Cu2+ through 1:1 stoichiometric chelation. The detection limit for Cu2+ ions was projected through linear quenching fitting to be as low as 2.77 × 10-8 M (or 1.77 ppb). The...

The detection of pyrophosphatase (PPase) activity is of great significance in diagnosing diseases and understanding the function of PPase-related biological events. This study constructed a turn off-on-off fluorescent system for PPase activity assay based on PPase-regulated competitive coordination of Cu2+ between a water-soluble fluorescent probe 6,7-dihydroxycoumarin (DHC) and pyrophosphate (...

Copper sulfate is a frequently used reagent for Microcystis blooms control but almost all the previous works have used Microcystis aeruginosa as the target organism to determine dosages. The aim of this study was to evaluate interspecific differences in the responses of various Microcystis species to varying Cu2+ concentrations (0, 0.05, 0.10, 0.25, and 0.50 mg L-1). The half maximal effective ...

A weak but significant similarity was found between the prion protein (PrP) and some transcription factors and zinc-finger proteins. A possible interpretation of this similarity is that the PrP is a metal- (copper-) binding transcription factor and might behave like a Zn-finger protein, with the Cu2+ binding to its histidine and serine residues. Copper-binding could create intramolecular bridge...