Transportation Of Cu Research Articles

Effects of low molecular weight organic acids on Cu accumulation by castor bean and soil enzyme activities

Chelating agents have been considered as an important phytoremediation strategy to enhance heavy metal extraction from contaminated soil. A pot experiment was conducted to explore the effects of low molecular weight organic acids (LMWOAs) on the phytoremediation efficiency of copper (Cu) by castor bean, and soil enzyme activities. Results indicated that the addition of all the three kinds of LMWOAs (citric, tartaric, oxalic acids) did not decrease the biomass of castor bean, despite the fact they reduced the concentration of chlorophyll-a in leaves compared to the control. The Cu concentrations in the roots and shoots significantly increased by 6–106% and 5–148%, respectively, in the LMWOAs treatments so that the total accumulation of Cu by whole plants in all the LMWOAs treatments increased by 21–189% in comparison with the control. The values of the translocation factor (TF) and bio-concentration factor (BCF) of Cu in castor bean also rose following the addition of LMWOAs, indicating that the LMWOAs enhanced the uptake and transportation of Cu. Moreover, the application of LMWOAs did not significantly change the soil pH but significantly increased the activity of soil enzymes (urease, catalase, and alkaline phosphatase). The addition of exogenous LMWOAs increased the available Cu significantly in the soil, thus promoted the phytoextraction efficiency of Cu by castor bean. These results will provide some new insights into the practical use of LMWOAs for the phytoremediation of heavy-metal-contaminated soil employing castor bean.

Active uptake of hydrophilic copper complex Cu(ii)-TETA in primary cultures of neonatal rat cardiomyocytes.

Myocardial ischemia leads to copper efflux from the heart. The ischemic tissue with a low copper content fails to take up copper from the circulation even under the conditions of serum copper elevation. Cardiac copper repletion thus requires other available forms of this element than those currently known to bind to copper transport proteins. The copper complex of triethylenetetramine (TETA) is a metabolite of TETA, which has the potential to increase cardiac copper content in vivo. In the present study, we synthesized Cu(ii)-TETA, analyzed its crystal structure, and demonstrated the role of this compound in facilitating copper accumulation in primary cultures of neonatal rat cardiomyocytes. The Cu(ii)-TETA compound formed a square pyramidal chloride salt [Cu(TETA)Cl]Cl structure, which dissociates from chloride in aqueous solution to yield the four-coordinate dication Cu(ii)-TETA. Cu(ii)-TETA was accumulated as an intact compound in cardiomyocytes. Analysis from time-dependent copper accumulation in cardiomyocytes defined a different dynamic process in copper uptake between Cu(ii)-TETA and CuCl2 exposure. An additive copper accumulation in cardiomyocytes was found when the cells were exposed to both CuCl2 and Cu(ii)-TETA. Gene silencing of copper transport 1 (CTR1) did not affect cross-membrane transportation of Cu(ii)-TETA, but inhibited copper cellular accumulation from CuCl2. Furthermore, the uptake of Cu(ii)-TETA by cardiomyocytes was ATP-dependent. It is thus concluded that the formation of Cu(ii)-TETA facilitates copper accumulation in cardiomyocytes through an active CTR1-independent transportation process.

Cu and S isotopic signatures of the Erdenetiin Ovoo porphyry Cu-Mo deposit, northern Mongolia: Implications for their origin and mineral exploration

The copper (δ65Cu) and sulfur (δ34S) isotope compositions of ore minerals from the Erdenetiin Ovoo porphyry Cu-Mo deposit in northern Mongolia were measured. The δ65Cu values of Cu (I) sulfide minerals ranged from 0.14‰ to 2.69‰, suggesting that Cu predominantly originated from magmatic sources, whereas Cu (II) minerals such as chrysocolla, malachite and azurite presented much larger variations of δ65Cu values from −1.01‰ to 10.0‰. The small difference between the primary and secondary Cu sulfide minerals indicates an insignificant influence of Cu isotope fractionation processes during their formation, which may be explained by large mass transport and/or the involvement of biogenic activities. The δ65Cu values of primary chalcopyrite suggest source heterogeneity and/or the occurrence of isotope fractionation under a high-temperature environment. The positive ΔCu (II) mineral − Cu (I) mineral values imply little transport of Cu in the deposit, with a rough mass balance and fast redox reaction.The δ34S values of the primary sulfide minerals (pyrite, molybdenite and chalcopyrite) clustered near 0‰, indicating that the sulfur is mainly derived from a homogeneous magmatic source. By contrast, the δ34S values of secondary Cu sulfide minerals ranged from −3.2‰ to −0.3‰, with an average of −1.6‰. The lower δ34S values are likely influenced by either S isotope fractionation processes or input of sulfur with different S isotope compositions during their formation.The measured δ65Cu and δ34S values of these ore minerals suggest a large mass transportation of Cu to an adjacent location, indicating little possibility of a hidden Cu occurrence in the Erdenetiin Ovoo deposit area.

In Situ Subcellular Imaging of Copper and Zinc in Contaminated Oysters Revealed by Nanoscale Secondary Ion Mass Spectrometry.

Determining the in situ localization of trace elements at high lateral resolution levels in the biological system is very challenging, but critical for our understanding of metal sequestration and detoxification. Here, the cellular and subcellular distributions of Cu and Zn in contaminated oysters of Crassostrea hongkongensis were for the first time mapped using nanoscale secondary ion mass spectrometry (nanoSIMS). Three types of metal-containing cells were revealed in the gill and mantle of oysters, including Cu-specific hemocytes, Cu and Zn-containing granular hemocytes, and Cu and Zn-containing calcium cells. Obvious intercellular distribution of Cu was found in the gill tissue, indicating the potential role of hemolymph in the transportation of Cu in oysters. The distribution of Cu showed a strong colocalization with sulfur and nitrogen in Cu-specific hemocyte and intercellular hemolymph. In the Cu and Zn-containing granular hemocytes and calcium cells, the co-occurrence of Cu and Zn with phosphorus and calcium was also found. Different relationships of distributions between Cu/Zn and macronutrient elements (nitrogen, sulfur and phosphorus) implied the differential metal complexation in oysters. Interestingly, quantitative analysis of the ratios of 32S-/12C14N- and 31P-/12C14N- of metal-deposited sites suggested the dynamic process of transfer of Cu and Zn from the metabolized protein pool to a more thermodynamically stable and detoxified form.

Pilot Study of 64Cu(I) for PET Imaging of Melanoma

At present, 64Cu(II) labeled tracers including 64CuCl2 have been widely applied in the research of molecular imaging and therapy. Human copper transporter 1 (hCTR1) is the major high affinity copper influx transporter in mammalian cells, and specially responsible for the transportation of Cu(I) not Cu(II). Thus, we investigated the feasible application of 64Cu(I) for PET imaging. 64Cu(II) was reduced to 64Cu(I) with the existence of sodium L-ascorbate, DL-Dithiothreitol or cysteine. Cell uptake and efflux assay was investigated using B16F10 and A375 cell lines, respectively. Small animal PET and biodistribution studies were performed in both B16F10 and A375 tumor-bearing mice. Compared with 64Cu(II), 64Cu(I) exhibited higher cellular uptake by melanoma, which testified CTR1 specially influx of Cu(I). However, due to oxidation reaction in vivo, no significant difference between 64Cu(I) and 64Cu(II) was observed through PET images and biodistribution. Additionally, radiation absorbed doses for major tissues of human were calculated based on the mouse biodistribution. Radiodosimetry calculations for 64/67Cu(I) and 64/67Cu(II) were similar, which suggested that although melanoma were with high radiation absorbed doses, high radioactivity accumulation by liver and kidney should be noticed for the further application. Thus, 64Cu(I) should be further studied to evaluate it as a PET imaging radiotracer.

The kinetic analysis of optimization and selective transportation of Cu(II) ions with TNOA as carrier by MDLM system

This study covers the transportation of Cu(II) ions by multi-dropped liquid membrane (MDLM) system and tri-n-octylamine (TNOA) as carrier in kerosene. Batch experiments are held to obtain optimum conditions for the transportation of Cu(II) ions such as volume of donor, organic, and acceptor phase 100ml, pH of donor phase 9.00, temperature 298.15K, concentration of H2SO4 in acceptor phase 1.00mol·L−1, concentration of TNOA in organic phase 5.00×10−3mol·L−1 and rate of peristaltic pump 50ml·min−1. Optimum circumstances of this extraction are as follows: pH of donor phase is 9.00, concentration of TNOA is 5.00×10−3mol·L−1, 1.00mol·L−1 H2SO4 as acceptor phase, and flux rate is 50ml·min−1. Cu(II) ion transportation is consecutive first order irreversible reaction. Activation energy is found as 5.22kcal·mol−1 (21.82kJ·mol−1), this process is called as diffusion controlled system. Selective transportation of Cu(II) ions with alkaline, alkaline earth, and different heavy metal ions at optimum conditions of single Cu(II) extraction was conducted. According to the selective transportation Cu(II) ions with alkaline and alkaline earth metal ions, Na+, K+, and Ba2+ ions are not detected in the acceptor phase, but 12.00% of Ca2+ ions is transported from donor phase to acceptor phase. At the end of the simultaneous extraction of Zn(II), Fe(III), and Mo(VI) with Cu(II) ions, 2.20% of Mo(VI), 0.80% of Fe(III) and 3.60% of Zn(II) are detected in the acceptor phase.

Alleviating effects of exogenous NO on tomato seedlings under combined Cu and Cd stress

To investigate the effect of NO on the different origin and regulation of oxidative stress of Cu and/or Cd, tomato seedlings were treated with Cu, Cd, or Cu + Cd in a nutrient solution culture system. The main effect of Cu(2+) was a significant reduction in root activity and nitrate reductase (NR) activity, which was similar to that under 50 μM Cd treatment, but promoted Cu accumulation. The supply of Cu under Cd treatment decreased Cd concentration, while not altered Cu concentration by contrast with Cu treatment, which is suggestive of a replacement of Cu(2+) with Cd(2+) and effective decrease in the boiotoxicity of 50 μM Cd(2+) to tomato seedlings. However, NO alleviated the restriction to NR activity significantly and made the biomass of tomato seedlings recover under Cd treatment, and also increased root activity under Cu and Cu + Cd treatment. Exogenous NO markedly reduced the absorption and transportation of Cu but did not obviously change the translocation of Cd to the aboveground parts under Cu + Cd treatment. Both metals induced lipid peroxidation via the decreasing activation of antioxidant enzymes. The antioxidant enzyme system worked differently under Cu, Cd, or Cu + Cd stress. The activities of peroxidase (POD) and catalase (CAT) were higher under single Cd stress than under the control. Meanwhile, Cu + Cd treatment decreased the activities of POD, superoxide dismutase (SOD), and ascorbic acid peroxidase (APX). Exogenous NO increased POD and SOD activities in the leaves and roots, and CAT activity in the roots under combined Cu and Cd stress. These results suggest that a different response and regulation mechanism that involves exogenous NO is present in tomato seedlings under Cu and Cd stress.

铜胁迫与外源乙烯相互作用对长春花幼苗生长和生理代谢的影响

铜是植物生长发育所必需的营养元素。本文以药用植物长春花(Catharanthus roseus)为材料，从长春花在铜胁迫的逆境条件下培养入手，并且辅助以外源乙烯调控，研究其对长春花初生代谢、Cu的富集和转运以及次生代谢等方面的协同效应。当铜胁迫浓度较低时叶绿素含量减少导致光合作用减弱；根部对Cu有着较强的富集能力，并且Cu在长春花植株体内由成熟组织向幼嫩组织转运率较高，在此基础上加入外源乙烯利后，降低了植株各组织部位对铜的富集能力，降低了铜胁迫对长春花植株的胁迫伤害，促进了铜由成熟叶片向幼嫩组织的转运率。这些结果表明，铜胁迫对长春花初生和次生代谢具有显著的抑制作用，外源添加乙烯不但可以缓解铜胁迫引起的生长抑制和生理伤害，同时对长春花叶片中生物碱的合成积累具有协同促进效应。 Copper is the essential nutrient for the growth and development of plants. Here, a medical plant Catharanthus roseus was subjected to different concentrations of copper plus with exogenous ethylene, investigating their cooperative effects on plant growth, primary metabolism, accumula-tion and transportation of Cu, as well as secondary metabolisms. Our results showed that the treatment with low level of Cu decreased chlorophyll content and photosynthetic rate. In addition, large amounts of Cu was accumulated in roots and brought about obvious hurt on root growth. In this case, the plant was able to actively transfer Cu from mature tissues to young ones. When ex-ogenous ethylene was applied, the accumulation of Cu in detected tissues was decreased, partly reducing the physiological hurt of copper stress on plant and largely promoting the Cu transport rate from mature leaves to young tissues. It was concluded that the copper stress exerted an ob-viously adverse effect on plant primary and secondary metabolism. An increased exogenous ethy-lene supply could not only alleviate the inhibitory effect of copper stress on plant growth, but en-hance vinblastine accumulation in plants.

Simultaneous Adsorption of Oxytetracycline and Copper(II) onto Loess Soil: Kinetics Properties and the Effects of pH

Oxytetracline (OTC) is a widely-used antibiotic, which could transport into aqueous and soil systems. The coexistence of heavy metals, such as copper (II) [Cu (II)], may change the adsorption behaviors of OTC onto soils. This study investigated the simultaneous adsorption behaviors of OTC Cu (II) onto loess soil, which is ubiquitous in the northwest of China. The kinetics experiments were conducted in single and binary systems for OTC and Cu, and the results showed that the kinetics data of both OTC and Cu could be well fitted by the pseudo-second-model model. The co-adsorption might increase the adsorption rate of both OTC and Cu. However, the effects of the complexation of OTC and Cu (II) on their adsorption amounts onto loess soil were quite different. The presence of Cu (II) could increase the uptake of OTC from pH 3.0 to 10.0. By contrast, the coexistence of OTC would decrease the uptake of Cu (II), especially at pH > 5.0. Hence, it is proposed that the migration of OTC might be slowed down by the coexistence of Cu (II), whereas the transportation of Cu (II) would be accelerated by the presence of OTC.

The effects of exogenous putrescine on sex-specific responses of Populus cathayana to copper stress

We used the dioecious tree, Populus cathayana, as a model species to study plants’ physiological and biochemical responses to copper (Cu) stress, exogenous putrescine (Put) treatment and their interaction. Although males accumulated higher Cu concentrations in leaves than did females under Cu stress, they did not suffer more damage than females, as reflected by changes in gas exchange, pigment contents, membrane lipid peroxidation (thiobarbituric acid reactive substances, TBARS) and protein oxidation (carbonyl). Higher Cu tolerance of males was correlated with a higher H2O2 scavenging ability and proline responses, and a better maintenance of non-protein thiols (NP-SHs) and spermine (Spm) contents. We also discovered that mitigation effects of exogenous Put on Cu stress occurred, as visible as a recovery of the total chlorophyll content, and lower TBARS and carbonyl under interaction treatment when compared to Cu stress alone. Exogenous Put decreased the Cu concentration in leaves of both sexes, but to different degrees. Such effects of exogenous Put suggested that Put may play important roles in the stabilization of membrane integrity and protein structures, and it may modulate the uptake and transportation of Cu. Our results indicated that (1) males are more tolerant to Cu stress than females; (2) Put could mitigate Cu toxicity in P. cathayana, but to a different degree in males and females; (3) males are better candidates than females for Cu extraction and phytoremediation.

Study on Transportation of Cu(II) by Dispersion Supported Liquid Membrane System

The transportation and separation of Cu(Ⅱ) through a dispersion supported liquid membrane(DSLM) consisting of 2-ethylhexyl Phosphonic Mono-(2-Ethylhexyl) in kerosene, supported on the polyvinylidene fluoride membrane(PVDF), is studied. The effects of pH value in the feed phase, volume ratio of liquid membrane phase and hydrochloric acid, concentrations of HCl in the strip phase and initial concentration of Cu(Ⅱ) in the feed phase are also researched. The results show that copper ion can be transported effectively when pH =5.25 in the feed phase, the volume ratio is160:40, concentrations of HCl in the strip phase is 4.0mol/L. Under the optimum transport conditions, when initial concentration of Cu(Ⅱ) was 2.00×10-4mol/L, the transport rate of Cu(Ⅱ)was up to 94.7% in 130 min.

Chemical Transportation of Heavy Metals in the Constructed Wetland Impacted by Acid Drainage

Chemical transportation of heavymetals in the constructed wetland impacted byacid drainage was investigated seasonallyusing a combination of the selective sequential extraction of the sediments with elemental analysis of the emergent vegetation in the wetland. Manganese was dissolved from sediments in the constructed wetland bythe contact with acid drainage, and then precipitated again as ionexchangeable forms. It was expected that a part of Mn and Fe bound to oxides were flown out of the wetland as suspended particulate matters. It was observed that there is passive absorption of Mn in leaves of Phragmites austlaris in the upstream of the wetland. The transportation of Cu clearlyshowed the seasonal variation: there was the decomposition of organic substances with high molecular weights bysoil microorganisms in summer. Therefore, Cu was complexed to the humic substances, and dramaticallyadosorbed onto the roots of Phragmites austlaris in down stream of the wetland. It was also observed that there is active absorption of Fe in roots and leaves of Phragmites austlaris. Most of the zinc was stronglybounded to the sediments, therefore, scarcelyuptaken to the vegetation. It was also found that there were heavymetal distributions between plant organs.

Effect of sublethal concentrations of copper on hemocyte number in bivalves

Seventy-five specimens of Sunetta scripta were exposed to 1, 3, and 5 ppm of Cu 2+, and sea water of 30‰ salinity, each, and 50 specimens of Villorita cyprinoides var. cochinensis to 0.15, 0.30 and 0.45 ppm of Cu 2+, and sea water of 15‰ salinity, each, for 5 days. Total hemocyte counts were made at every 24 hr. Statistical comparisons of the data indicated that total cell counts in the experimentals of S. scripta did not vary significantly from the controls at any time period. In 0.15 and 0.30 ppm Cu 2+-dosed V. cyprinoides var. cochinensis total cell counts were significantly lower than the controls at 48, 72, 96, and 120 hr, and in 0.45 ppm Cu 2+-dosed ones at all time periods. It is indicated that in the former species because the concentration range of Cu 2+ was far below the lethal dose, or because of the low uptake rate of copper in high salinity, Cu 2+ ions might not have entered the system in sufficient quantity to cause cell mortality and/or to induce the involvement of hemocytes in the transportation of Cu 2+ ions to sites of storage and excretion. On the contrary, in the latter species it is indicated that because the concentration range of Cu 2+ was close to LC 50 value, or because of the high uptake rate in low salinity, Cu 2+ ions might have entered the system in sufficient quantity to cause cell mortality and/or induce the involvement of hemocytes in the transportation of Cu 2+ ions to sites of storage and excretion, thereby effecting significant flucturations in total hemocyte counts.

The interaction of copper(II) and glycyl-l-histidyl-l-lysine, a growth-modulating tripeptide from plasma

The interaction between Cu(II) and the growth-modulating tripeptide glycyl-L-histidyl-L-lysine in the presence and absence of L-histidine was investigated by potentiometric titration and visible-absorption spectrophotometry at 25 degrees C in 0.15 M-NaCl. Analyses of the results in the pH range 3.5--10.6 indicated the presence of multiple species in solution in the binary system and extensive amounts of the ternary complexes in the ternary system. The species distribution and the stability constants, as well as the visible-absorption spectra of the species, were evaluated. The combined results were used to propose the structure of some of the complexes. The influence of the epsilon-amino group of the peptide in the enhancement of the stability constants was reflected prominently when compared with those complexes formed by either glycyl-L-histidine or glycyl-L-histidylglycine. The results obtained from the equilibrium-dialysis experiments showed that this tripeptide was able to compete with albumin for Cu(II) at pH 7.5 and 6 degrees C. At equimolar concentrations of albumin and the peptide, about 42% of the Cu(II) was bound to the peptide. At the physiologically relevant concentrations of Cu(II), albumin, L-histidine and this peptide, about 6% of the Cu(II) was associated with the low-molecular-weight components. This distribution could be due to the binary as well as the ternary complexes. The possible physiological role of these complexes in the transportation of Cu(II) from blood to tissues is discussed.