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Objective To assess the acute toxicity of Cu2+, Cd2+, Hg2+ and Pb2+ to Oncomelania hupensis. Methods Cu2+, Cd2+, Hg2+ and Pb2+ solutions were prepared at five concentrations, and 10 snails were exposed to each concentration for 24, 48, 72 h and 96 h. Then, the inhibition of snail activity and snail death was observed, and the half maximal effective concentration (EC50) and median lethal concentrations (LC50) were estimated. Results The 24, 48, 72 h and 96 h EC50 values of Cu2+, Cd2+, Hg2+ and Pb2+ were 0.74, 0.56, 0.46, 0.37 mg/L, 4.79, 3.52, 1.70, 1.26 mg/L, 1.90, 1.49, 0.83, 0.76 mg/L and 21.40, 9.98, 7.90, 5.42 mg/L for snails, respectively. The 96 h LC50 values of Cu2+, Cd2+, Hg2+ and Pb2+ were 0.43, 2.96, 1.12 mg/L and 12.22 mg/L for snails, the safe concentrations were 0.004 3, 0.029 6, 0.011 2, 0.122 2 mg/L, respectively. Conclusion Cu2+ shows a high acute toxicity to snails, and Cd2+ and Hg2+ exhibit a moderate acute toxicity to snails, while Pb2+ is lowly toxic to snails.
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Objective To evaluate the effects of Cu2+ and Cd2+ at different concentrations on superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity in Oncomelania hupensis. Methods Cu2+- and Cd2+-containing solutions were prepared at 7 concentrations, and O. hupensis snails were exposed to the solutions for 24 h, of 15 snails in each concentration. Then, the snail body was collected following removal of the snail shell and homogenated, and the SOD, CAT and POS activities were detected in the supernatants. Results With the increase of the Cu2+ concentration, the SOD activity appeared a rise followed by a reduction in O. hupensis snails, and the CTA activity appeared a decline-rise-decline tendency, while the POD activity showed a tendency towards rise followed by decline. With the increase of the Cd2+ concentration, the SOD activity appeared a rise followed by a reduction in O. hupensis snails, and the CTA activity appeared a decline- rise- decline tendency, while the POD activity showed a decline-rise-decline tendency. Conclusion Exposure to Cu2+ and Cd2+ at high concentrations results in a decline in the activity of SOD, CAT and POD in O. hupensis at the same time.
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Objective: To prepare morin-Cu2+ complex imprinted polymer (CIP) and use the polymer to extract morin from mulberry branch. Methods: Morin-Cu2+ CIPs were prepared in water-methanol polar solvent in the presence of Cu2+, acrylamide as the functional monomer. The CIPs were used as the solid phase extraction sorbent for extracting morin from mulberry branch. Results: The prepared CIPs had specific and selective adsorption on morin, the maximum adsorption capacity was 82 μmol/g, which was much higher than that of the traditional imprinted polymers relying on hydrogen bond and non-imprinted polymers. The separation factors of CIPs to daidzein and catechin were 4.81 and 4.02, respectively. CIPs had a significant enrichment effect on morin in the composition of the mulberry branch solid phase extraction elution solution. Conclusion: Morin-Cu2+ CIPs are excellent material used for the separation and enrichment of morin, the material has good selective adsorption ability and environmental adaptability.
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Objective:To investigate the effect of copper ion(Cu2+) on the aggregation and neurotoxicity of Aβ, and affirm the role of Danggui Shaoyaosan in vitro,the Neuroblastoma (SH-SY5Y) cells treated with β-amyloid 1-42 (Aβ1-42) and Cu2+ were used as a vitro models of Alzheimer's disease(AD). Method:Aβ 1-42 (20 μmol·L-1) was reacted with different concentrations of copper sulfate (CuSO4,20,40 μmol·L-1), and then the thioflavine T (ThT) staining method was used to detect the Aβ aggregation state. The Aβ aggregation status was also detected by ThT staining in the Aβ1-42-Cu2+ group(20+20 μmol·L-1), and Danggui Shaoyaosan groups(1.6,3.2,6.4 mg·L-1).The SH-SY5Y cells were cultured and incubated with different concentrations of Aβ1-42(1.25,2.5,5,10,20,40 μmol·L-1) and Danggui Shaoyaosan(1.6, 3.2, 6.4,12.8 mg·L-1) for 24 h. Subsequently, SH-SY5Y cells were incubated with Aβ1-42 (20 μmol·L-1) and CuSO4(20 μmol·L-1) in the Aβ1-42-Cu2+ group, and incubated with Aβ1-42 (20 μmol·L-1), Danggui Shaoyaosan (1.6 mg·L-1) and CuSO4 (20 μmol·L-1) in Danggui Shaoyaosan group. Control group was added with the medium. After 24 h of co-action, the cell viability was detected by the methylthiazolyl tetrazolium (MTT) assay. The morphology of the cells was photographed by microscopy. The intracellular extracellular Aβ1-42 aggregation was detected by Western blot. Result:Cu2+ and Aβ1-42 bound to more and larger Aβ aggregates compared with the Aβ1-42 group. Compared with the normal group, cell viability was significantly reduced (PPβ1-42 aggregation was increased(PPβ-Cu2+ (PPβ1-42 protein (PPConclusion:Cu2+ can increase the aggregation and toxicity of Aβ; Danggui Shaoyaosan can significantly reduce the damage of SH-SY5Y cells induced by Cu2+-mediated Aβ aggregation, promote Aβ endocytosis, reduce extracellular Aβ aggregation and increase cell viability.
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We developed a rapid method to detect Cu2+and glutathione(GSH)based on the fluorescence quenching-recovery properties of graphene quantum dots(GQDs),which were synthesized by the gentle oxidation of graphite powder.The results revealed that the fluorescence intensity of GQDs versus concentration of Cu2+and GSH had good linearity, with the detection limits of 0.01 and 0.1 mmol/L, respectively.The fluorescence quenching was linearly proportional to the concentrations of Cu2+ranging from 1.0 to 10.0 mmol/L;the fluores-cence intensity was linearly enhanced with the concentrations of GSH ranging from 0.1 to 1.0 mmol/L.In addi-tion,the method was successfully applied to the determination of real samples with recoveries falling between 93%-101% and 96%-107%,respectively.This method is simple,accurate and precise.There was no interference with other familiar co-existing metal ions and potential materials.
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The present study explored the effects of Cu²⁺enrichment and release on the growth and internal quality of Whitmania pigra, and the regularity of enrichment and release in different tissues of Wh. pigra. In the range of safe concentration(SC), a certain concentration of Cu²⁺ was added to the Wh. pigra for 50 days, and stopped adding for another 50 days. The growth index of Wh. pigra, Cu²⁺ content in different tissues, and the internal quality were determined. The results showed that the average body weight of Wh. pigra in 0.014 mg·L⁻¹ of Cu²⁺ group was significantly higher than that in control group during the experimental period (<0.05), and the mortality rate was lower than that in the control group. The specific growth rate, digestive enzyme activity, growth and digestive enzyme related gene expression of Wh. pigra in Cu²⁺ group were significantly higher than that in the control group (<0.05) during the early 40 days of enrichment, and there was no significant difference in the release period. In Cu²⁺ group, the expression of immune enzyme and immune enzyme related gene of Wh. pigra increased first and then decreased compared with control group (<0.05). The ability of enriched Cu²⁺ in different tissues of Wh. pigra was digestive tract>muscle>skin. The ability of release Cu²⁺ was muscle>digestive tract>skin. There was no significant difference in the internal quality and hirudin gene expression between Cu²⁺ group and control group. In conclusion, Cu²⁺ can improve the expression of digestive enzymes, immune enzyme and related genes of Wh. pigra, promote the growth of Wh. pigra and enhance their immunity, but it doesn't affect the internal quality of Wh. pigra. The Wh. pigra can completely release Cu²⁺ within 30 days.
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ABSTRACT Proteins have been the subject of electrochemical studies. It is possible to apply electrochemical techniques to obtain information about their structure due to the presence of five electroactive amino acids that can be oriented to the outside of the peptidic chain. These amino acids are L-Tryptophan (L-Trp), L-Tyrosine (L-Tyr), L-Histidine (L-His), L-Methionine (L-Met) and L-Cysteine (L-Cys); their electrochemical behavior being subject of extensive research, but it is still controversial. No spectroscopic investigations have been reported on L-Trp, and due to the short life time of the intermediates, ex situ techniques cannot be employed, leading to a never-ending discussion about possible intermediates. In the L-Tyr and L-His cases, spectroelectrochemical studies were performed and different intermediates were observed, suggesting that some intermediates may be observed under specific conditions, as proposed for L-Cys. This amino acid is the most interesting among the electroactive ones because of the presence of a thiol moiety at its side chain, leading to a wide range of oxidation states. It can adsorb onto surfaces of different crystallographic orientation in stereoselective conformation, modifying the surface for different applications.as a surface engineering tool since it plays the role of as an anchor for the growing of nanocrystals inside proteic templates.
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Oxidation-Reduction , Amino Acids/chemistry , Adsorption , Electrochemistry , NanoparticlesABSTRACT
Objective To detect the transcription factors of copper ion (Cu,2+) metabolism and oxidative stress by Candida albicans knocked down different transcription factors.Methods Spot assay, growth curve were used.Results The sensitivity to Cu,2+ in Cup2Δ/Δ was increasing and the growth of Cup2Δ/Δ was inhibited in 5 mmol /L Cu,2+ medium.The results showed that Cup2Δ/Δ also increased the sensitivity to H2O2, interestingly, Cu,2+and H2O2 played a synergistic antifungal effect.The tolerance of Cup2Δ/Δ and SN250 to H2O2 induced oxidative stress was increased after BCS chelating Cu,2+.In the fluconazole, miconazole and ketoconazole susceptibility experiments, Cup2Δ/Δ did not show susceptibility to azole drugs.Conclusion Knockout transcription factor Cup2, which could increase the sensitivity to Cu,2+ and H2O2in Candida albicans.Transcription factor Cup2 might be involved in the regulation and control of Candida albicansmetabolism on Cu,2+ and oxidative stress induced by H2O2, but not involved in the regulation and control of drug resistance to azole drugs.
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The water-soluble 3-mercaptopropionic acid (MPA)-stabilized CdTe (MPA-CdTe) quantum dots (QDs) were synthesized by aqueous suspension.The study showed that the fluorescence quenching process of Cu2+ to MPA-CdTe QDs,whose largest emission peak was 599 nm,could be described well by the theory of fluorescence quenching in competitive absorption systems and its modification of Stern-Volmer equations.By fittings,the results showed a good polynomial relationship between the fluorescence intensity F0/F and the concentration of Cu2+,when the concentration was in the range of 2.28 × 10-6-18.24 × 10-6 mol/L and 4.8 × 10-7-12 × 10-7 mol/L,and two polynomial equations were respectively elucidated based on dynamic and static quenching in competitive-absorption systems:F0/F =7.999-2.470c +0.339 c2,F0/F =3.154-0.160 c +0.049 c2 and degree of fitting are 0.991 and 0.993,respectively.The detection limit was 1.326 × 10-7.
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Abstract Oxidative enzymes secreted by white rot fungi can be applied in several technological processes within the paper industry, biofuel production and bioremediation. The discovery of native strains from the biodiverse Misiones (Argentina) forest can provide useful enzymes for biotechnological purposes. In this work, we evaluated the laccase and manganese peroxidase secretion abilities of four newly discovered strains of Trametes sp. that are native to Misiones. In addition, the copper response and optimal pH and temperature for laccase activity in culture supernatants were determined.The selected strains produced variable amounts of laccase and MnP; when Cu2+ was added, both enzymes were significantly increased. Zymograms showed that two isoenzymes were increased in all strains in the presence of Cu2+. Strain B showed the greatest response to Cu2+ addition, whereas strain A was more stable at the optimal temperature and pH. Strain A showed interesting potential for future biotechnological approaches due to the superior thermo-stability of its secreted enzymes.
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Fungal Proteins/metabolism , Laccase/metabolism , Trametes/enzymology , Argentina , Temperature , Enzyme Stability , Fungal Proteins/genetics , Fungal Proteins/chemistry , Laccase/genetics , Laccase/chemistry , Trametes/isolation & purification , Trametes/geneticsABSTRACT
The fluorescence of Rhodamune B could be quenched by the manner of photo-unduced electron transfer wuth Cu2-x Se nanopartucles as the energy receptor and Rhodamune B as the energy donor. However, L-cysteune was capable of recoverung the fluorescence of Rhodamune B, and the fluorescence untensuty was proportuonal to the concentratuons of L-cysteune. Based on that, a novel method for detectung L-cysteune was establushed. After muxung L-cysteune and Rhodamune B pretreated by Cu2-x Se nanopartucles at pH 4. 6 and 30℃ for 2 mun, a lunear relatuonshup was obtauned between the fluorescence untensuty of Rhodamune B at 575 nm and the concentratuons of L-cysteune un the range of 2. 5 ×10-7-1. 1 ×10-6 mol/L. Thus method was used un the determunatuon of L-cysteune wuth a detectuon lumut (3σ/k) of 5. 5×10-8 mol/L. The common amuno acuds presented luttle unterference for the L-cysteune detectuon.
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Objective: To prepare rutin-Cu2+ complex imprinted polymer and study its adsorption ability. Methods: The polymer was prepared in mixed poler solvent, using α-methacrylic acid as functional monomer. The structure and preparation mechanism were studied by UV-vis spectroscopy and IR spectroscopy. Results: The polymer and rutin-Cu2+ complex were combined by coordinate bond and intermolecular force, the polymer had remarkably specific adsorption to complex of rutin-Cu2+. Conclusion: Rutin-Cu2+ complex molecularly imprinted polymer has great adsorption and specific identification to rutin-Cu2+, and can be used in extraction and separation of Chinese medicine effective constituent rutin.
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OBJECTIVE To study the roles of copper transporter 1 (CTR1 )and Cu2 + transporting ATPase αpolypeptide (ATP7A)in lead exposure-induced copper accu mulation and oxidative stress in rat C6 glio ma cells.METHODS Methyl thiazolyl tetrazoliu m (MTT)assay was performed to determine the proper Pb doses (without affecting cell viability)by treated the cells with lead acetate 0 -100 μmol·L -1 for 24 h and 48 h.Superoxide dis mutase (SOD)activity or malondialdehyde(MDA)level were detected respectively by xanthine oxidase technique and thiobarbituric acid (TBA) method.Ato mic absorption spectrophoto metry was e mployed to determine the intracellular levels of Pb and Cu ions.Real-ti me quan-titative PCR and Western blot were used to detect the mRNA and protein levels of CTR1 and ATP7A, respectively.RESULTS The cell viability significantly decreased when the doses of Pb treat ment was higher than 10 μmol·L -1 ,so 10 μmol·L -1 was chosen as a working concentration of Pb exposure in this study.Co mpared with those in the normal controls,a moderately decreased T-SOD activity and an increased MDA level was determined in the cells treated with Pb 10 μmol·L -1 or Cu 5 μmol·L -1 alone, while a significant drop of T-SOD activity and a re markable increase of MDA level was found in the cells co-exposed to Pb and Cu (P<0.01 ).Pb exposure for 24 and 48 h increased the cellular Cu uptake by 1 .2 and 2.5 fold,respectively (P <0.01 ).Evidences fro m RT-PCR showed that Pb exposure for 24 and 48 h upregulated the CTR1 mRNA level by 23.2% and 58.7%,and downregulated the ATP7A mRNA level by 58.1 % and 50.0%,respectively.Results fro m Western blot confirmed that Pb exposure also resulted in an increased CTR1 expression and a decreased ATP7A expression at protein level (P<0.01 ).CONCLUSION Pb exposure lead to Cu accu mulation,by affecting the expression levels of CTR1 and ATP7A,and increased oxidative stress in C6 cells.
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The present investigation reports, the novel synthesis of Copper and Copper oxide nanoparticles using Chemical reduction method and its physicochemical characterization. The nanoparticles have been prepared using Copper (II) succinate as precursor. Copper nanoparticles are initially formed and subsequently oxidized to copper oxide. As reported the nanoparticles were characterized by UV–visible spectroscopy, Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction measurements (XRD) and scanning electron microscopy (SEM). SEM analysis exhibited nanoparticles with an average diameter of about 45nm. XRD analysis revealed broad pattern of fcc crystal structure of copper metal and cubic cuprites structure for Cu2O. The antimicrobial properties of copper nanoparticles were investigated using Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The bactericidal effects of copper nanoparticles were studied based on diameter of inhibition zone in disk diffusion tests of nanoparticles dispersed in batch cultures. The copper nanoparticles showed excellent activity against Escherichia coli and Staphylococcus aureus, with excellent inhibition zones of 14 mm and 10 mm, respectively. Bacterial sensitivity to nanoparticles was found to vary depending on the microbial species.
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The abandoned mushroom compost of Flammulina velutipes, a cheap and easy by-product to get, was used as biosorbent for removing copper ions from aqueous solution. Batch experiments were carried out to investigate the effect of contact time, solution pH, biomass dosage, initial concentration of Cu2+ ions and temperature on biosorption efficiency. The maximum sorption capacity could be reached at pH 5.0 in 60 min. Langmuir, Freundlich, and Redlich- Peterson isotherm models were used to fit the experimental data and their model parameters were evaluated. The calculated qm based on Langmuir equation was 35.608 mg g-1 at 288 K, 48.711 mg g-1 at 298 K, and 42.330 mg g-1 at 308 K, respectively. The kinetics were discussed by pseudo- first order and pseudo- second order models, and the result showed that the latter was more suitable. The thermodynamics of biosorption was also investigated, and the biosorption process was feasible, spontaneous and endothermic in nature.
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Objective To study the catalytic capability of glucosamirie-Cu( Ⅱ) complex for decomposition of H2O2 and its relative factors. Methods Glucosamine-Cu( Ⅱ ) complex was prepared by the reaction of D-glucosamine hydrochloride with Cu2+ in aqueous solution, then added it into H2O2 solution. The concentration of H2O2 was determined by titrimetric analysis in a regular interval of time, the rate of decomposition of H2O2 was obtained in various conditions. Results Strong catalytic capability of glucosamine-Cu( Ⅱ ) complex was obtained at 30℃ pH 6. 5, the rate of decomposition was over 90% after 12h, and was almost 100% after 24h. Conclusion The complex of glucosamine-Cu( Ⅱ ) showed good catalytic capability for decomposition of H2O2.
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Using the high efficient copper-adsorbing yeast strain Y17 as absorbing material, the major affect factors including pH, original concentration of Cu2+, cell biomass, adsorption time and temperature were examined, and then the absorbing sites of the Y17 was determined. The results showed that the solution pH was the most dominate factor which affected the biosorption of Cu2+, the other affecting factors were the ini- tial concentration of Cu2+, the cell biomass added, and adsorption time, respectively; the temperature had lit- tle effect on the rate of biosorption. The orthogonal experiment showed that the optimal absorption condition was as follow: the solution pH was 5.0, the absorption time was 40 min, the cell biomass of Y17 added was 5.0 g/L, and the concentration of Cu2+ was 8 mmol/L; the highest adsorbing rate was up to 82.7% at this condition. Based on the results of different pretreatments and the desorption of Cu2+, the cell wall of Y17 was identified as the main place occurring boisorption process, and the -NH2 group, -COOH group on the surface of the yeast cells played an important role on the boisorption process.
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The effects of Cu2+ on superior cervical sympathetic ganglion of rabbits were studied by the sucrose-gap method. Cu2+ at cumula- tive concentration inhibited ganglion action potentials. IC50 of Cu2+ was 0.26 mmol/L. The effects of Cu2+ were antagonized by neostig-miae and L-cystein, while enhanced under 1/2[Ca2+] and reduced under 3[Ca2+] .Cu2+ inhibited ganglionic N wave and P wave,without affecting LN wave.
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Using the animal model of acute myocardial infarction of rabbit after left coronary artery ligation, the authors studied the reltionship between the change of myocardial K~+/Na~+ ,Mg~(2+)/Ca~(2+), and Zn~(2+)/Cu~(2+) ratio and the time after acute myocardial infarction. The results demonstrated that. (1)the K+/Na~+ and Mg~(2+)/Ca~(2+)ratio dropped with prolongation of time myocardial ischemia. There was significant (P0.05)difference of Zn~(2+)/Cu~(2+) ratio between the experimental groups and the control group, but Zn~(2+)/Cu~(2+) ratio showed a tendency of dropping with prolongation of time of ischemia in the experimental group. At 120 min of myocardial ischemia,the Zn~(2+)/Cu~(2+) ratio was abour 1/2 as those at 15min, 30min, and 60min(P
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Effects of Cu2+,Zn2+and Mn2+ on responses to ACh were studied with toad rec-tus abdominis. Cu2+, Zn2+and Mn2+concentra-tion- dependently shifted the concentration-response curves for ACh to the right unparallelly and reduced the maximal response considerably. The pAh values of Cu2+ , Zn2+ and Mn2+ were 3.69, 2.95 and 2. 62, respectively. The inhibitory potent of Cu2+ and Zn2+ seemed to be 11.7 times and 2. 1 times respectively more thanthat of Mn2+. It was suggested that Cu2+, Zn2+ and Mn2+postsynaptically interfere with the action of ACh. However, Zn2+in lower concentration shifted the bottom section of the curve for ACh to the left and top, and shifted the top section of the curve to the right, suggesting that Mn2+in lower concentration be possessed of partial agonistic property.