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Combined fluorescence and electrochemical investigation on the binding interaction between organic acid and human serum albumin

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Journal of environmental Sciences 2009年第3期21卷 373-379页

作者： CHEN Yan-Min,guo liang-hong state key laboratory of environmental chemistry and ecotoxicology,Research Center for Eco-environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China. state key laboratory of environmental chemistry and ecotoxicology Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Human serum albumin （HSA） is a plasma protein responsible for the binding and transport of fatty acids and a variety of exogenous chemicals such as drugs and environmental pollutants. Such binding plays a crucial role in determining the ADME （absorption, distribution, metabolism, and excretion） and bioavailability of the pollutants. The binding interaction between HSA and acetic acid （C2）, octanoic acid （C8） and dodecanoic acid （C12） has been investigated by the combination of site-specific fluorescent probe, tryptophan intrinsic fluorescence and tyrosine electrochemistry. For the study of the fatty acid interaction with the two drug-binding sites on HSA, two fluorescent probes, dansylamide and dansyl-L-proline were employed in the displacement measurements. Intrinsic fluorescence of tryptophan in HSA was monitored upon addition of the fatty acids into HSA. Electrocatalyzed response of the tyrosine residues in HSA by a redox mediator was used to investigate the binding interaction. Qualitatively, observations from these three approaches were very similar. HSA did not show any change in the fluorescence and electrochemical experiments after mixing with C2, suggesting there is no significant interaction with the short-chain fatty acid. For C8, the measured signal dropped in a single-exponential mode, indicating an independent and non-cooperative binding. The calculated association constant and binding ratio were 3.1 × 10^6 L/mol and 1 with drug binding Site Ⅰ, 1.1 × 107 L/mol and 1 with Site Ⅱ, and 7.0× 0^4 L/mol and 4 with the tryptophan site, respectively. The measurements with C12 displayed multiple phases of fluorescence change, suggesting cooperativity and allosteric effect of the C12 binding. These results correlate well with those obtained by the established methods, and validate the new approach as a viable tool to study the interactions of environmental pollutants with biological molecules.

关键词： absorption, distribution, metabolism, and excretion (ADME) organic acid human serum albumin fluorescence electrochemistry

Effects of maize root exudates and organic acids on the desorption of phenanthrene from soils

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Journal of environmental Sciences 2009年第7期21卷 920-926页

作者： ZHU Yanhong, ZHANG Shuzhen, huang honglin, WEN Bei state key laboratory of environmental chemistry and ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. state key laboratory of environmental chemistry and ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

The effects of maize root exudates and low-molecular-weight-organic anions （LMWOAs） on the desorption of phenanthrene from eight artificially contaminated soils were evaluated. A significant negative correlation was observed between the amounts of phenanthrene desorbed and the soil organic carbon （SOC） contents （P 〈 0.01）, and the influences of soil pH and clay content on phenanthrene desorption were insignificant （P 〉 0.1）. Neither maize root exudates nor oxalate and citrate anions influenced desorption of phenanthrene with the addition of NaN3. A faster phenanthrene desorption occurred without the addition of NaN3 in the presence of maize root exudates than oxalate or citrate due to the enhanced degradation by root exudates. Without the addition of NAN3, oxalate or citrate at different concentrations could inhibit phenanthrene desorption to different extents and the inhibiting effect by citrate was more significant than by oxalate. This study leads to the conclusion that maize root exudates can not enhance the desorption under abiotic condition with the addition of NaN3 and can promote the desorption of phenanthrene in soils without the addition of NaN3.

关键词： phenanthrene desorption low-molecular-weight-organic anions (LMWOAs) root exudates soils

Levels and distributions of polychlorinated biphenyls in sewage sludge of urban wastewater treatment plants

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Journal of environmental Sciences 2009年第4期21卷 468-473页

作者： guo Li, ZHANG Bing, XIAO Ke, ZHANG Qinghua, ZHENG Minghui state key laboratory of environmental chemistry and ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences,Beijing 100085, China state key laboratory of environmental chemistry and ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Concentrations of polychlorinated biphenyls （PCBs） have been measured in sewage sludge samples from 8 urban wastewater treatment plants in Beijing, China. The PCB congeners were analyzed by isotope dilution high resolution gas chromatography/high resolution mass spectrometry method. The concentration of PCBs ranged from 65.6 to 157 ng/g dry weight （dw）, with a mean value of 101 ng/g dw. The dioxin-like PCB WHO-TEQs （World Health Organization-Toxic Equivalents） of the sludge were lower than 1 pg /g dw. Consequently, all the concentrations of PCBs in sludge samples were below the upper limit for land application according to the Chinese legislation law for agriculture use. The PCB homologue profiles in sludge samples were dominated by tri-CBs and tetra- CBs. Similar distributions have been found in one of the Chinese PCB commercial products. The patterns of dioxin-like and indicator congeners observed in this study were quite similar in all samples. The predominant congener for dioxin-like and indicator PCBs were PCB-118 and PCB-28, respectively, while PCB-126 had the highest TEQ value.

关键词： polychlorinated biphenyls wastewater treatment plant sewage sludge distribution

Detection of Peptide Damage Induced by Fenton Reaction with Electrochemical Biosensor

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生物物理学报 2009年第S1期25卷 400-401页

作者： Na Qu, liang-hong guo and Ben-Zhan Zhu state key laboratory of environmental chemistry and ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.

Hydroxyl radical is one of the most reactive oxygen species (ROS) in biological systems, which can react with proteins and result in protein oxidation and damage. Oxidative

关键词： Electrochemical Biosensor Peptide Damage Fenton Reaction Hydroxyl radical

One-step and high-density protein immobilization on epoxysilane-modified silica nanoparticles

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Chinese Science Bulletin 2009年第15期54卷 2620-2626页

作者： ZHANG Qin huang rongfu guo liang-hong state key laboratory of environmental chemistry and ecotoxicology Research Center for Eco-environmental Sciences ChineseAcademy of Sciences Beijing 100085 China

Silica nanoparticles are most commonly modified with amino-silanes, followed by post-modification activation for protein immobilization. In this work, epoxy-functionalized silica nanoparticles were prepared by modification with glycidyloxypropyl trimethoxysilane (GPTMS) for direct protein immobilization. Silica nanoparticles possessed an average size of 46 nm, but increased to 63 nm after GPTMS modification. Reaction time, reaction temperature and GPTMS content had no significant effect on particle size. Zeta potential of SiO2 changed from ?26mV to +38mV after modification. Fourier-transformed infrared spectroscopy revealed alkyl C-H bending and stretching bands at 2944 cm-1, 1343 cm-1 and 1465 cm-1, respectively, for the modified nanoparticles. Fluorescein cadaverine was found to bind to GPTMS-modified SiO2, but not to bare SiO2, indicating the chemical reactivity of epoxy groups on the modified nanoparticle with amines. Finally, fluorescently labeled bovine serum albumin (BSA) was used as a model protein to investigate the capacity of epoxy-SiO2 nanoparticles for protein immobilization. The results showed that more proteins were immobilized on the particle with longer reaction time, higher NaCl concentration, lower pH, and less GPTMS content. More importantly, proteins bound to epoxy-SiO2 nanoparticle were highly stable. Under optimized reaction conditions, as much as 25 mg BSA/g nanoparticle was covalently attached to the nanoparticle. The epoxy silane modification of silica nanoparticles offers a reactive surface for one-step and high-density protein immobilization.

关键词：二氧化硅制备方法反应条件纳米粒子

Detection of Peptide Damage Induced by Fenton Reaction with Electrochemical Biosensor

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Detection of Peptide Damage Induced by Fenton Reaction with ...

Reactive oxygen species-mediated synergistic cytotoxicity of human liver cells between pentachlorophenol and copper-1,10-phenanthroline complex

第十一次中国生物物理学术大会暨第九届全国会员代表大会

作者： Na Qu,liang-hong guo and Ben-Zhan Zhu state key laboratory of environmental chemistry and ecotoxicology,Research Center for Eco-environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China.

＜正＞Hydroxyl radical is one of the most reactive oxygen species（ROS）in biological systems,which can react with proteins and result in protein oxidation and *** damage

关键词： Electrochemical Biosensor Peptide Damage Fenton Reaction Hydroxyl radical

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Reactive oxygen species-mediated synergistic cytotoxicity of...

Low Doses of Bisphenol A Induce Mouse Spermatogonial Cell Proliferation by G-Protein-Coupled Receptor 30 and Estrogen Receptor-α

中国活性氧生物学效应学术会议

作者： Zhi-guo Sheng and Ben-Zhan Zhu state key laboratory of environmental chemistry and ecotoxicology,Research Center for Eco-environmental Science,Chinese Academy of Sciences

Chemical pollutants often co-occur and these co-occurring toxicants may interact to produce unexpected combined toxic *** pentachlorophenol(PCP) and copper-1,10-phenanthroline (Cu(OP)),used as wood preservatives,co-exist near the wood-preserving facilities and body fluids/tissues of people non-occupationally *** previous studies have shown that a combination

关键词： pentachlorophenol copper-1,10-phenanthroline synergistic cytotoxicity apoptosis mitochondrial ROS XIAP HL-7702 HepG2

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Low Doses of Bisphenol A Induce Mouse Spermatogonial Cell Pr...

Cytotoxicity and autophagy induction by graphene quantum dots with different functional groups

第六届全国环境化学大会暨环境科学仪器与分析仪器展览会

作者： Zhi-guo Sheng1 and Ben-Zhan Zhu~(1,2) (1state key laboratory of environmental chemistry and ecotoxicology,Research Center for Eco-environmental Science,Chinese Academy of Sciences,Beijing 100085,P.R.China Linus Pauling Institute,Oregon state University,Corvallis,OR 97331)

＜正＞Bisphenol A（BPA） is one of the most prevalent chemicals for daily use materials, and human exposure to BPA is ubiquitous. BPA has estrogenicity generally mediated by nuclear estrogen receptors（ERs）.However, low concentrations of BPA stimulates seminoma cell proliferation by an uncertain mechanism that does not involve activation of ERs. The present study aims to investigate the possible promoting effects of low dose BPA on the murine ER-βnegative GC-1 spermatogonial cells and the possible

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Journal of environmental Sciences 2019年第3期31卷 198-209页

作者： Yichun Xie Bin Wan Yu Yang Xuejing Cui Yan Xin liang-hong guo state key laboratory of environmental chemistry and ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences University of Chinese Academy of Sciences CAS key laboratory for Biomedical Effects of Nanomaterials and Nanosafety National Center for Nanoscience and Technology of China Institute of Environment and Health Jianghan University

Graphene quantum dots(GQDs) possess great potential in various applications due to their superior physicochemical properties and wide array of available surface ***, the toxicity of GQDs has not been systematically assessed, thus hindered their further development; especially, the risk of surface modifications of GQDs is largely unknown. In this study, we employed a lung carcinoma A549 cells as the model to investigate the cytotoxicity and autophagy induction of three types GQDs, including cGQDs(COOH-GQDs), hGQDs(OH-GQDs), and aGQDs(NH_2-GQDs). The results showed hGQDs was the most toxic, as significant cell death was induced at the concentration of 100 μg/mL,determining by WST-1 assay as well as Annexin-V-FITC/PI apoptosis analysis, whereas cGQDs and aGQDs were non-cytotoxic within the measured concentration. Autophagy detection was performed by TEM examination, LC3 fluorescence tracking, and Westernblot. Both aGQDs and hGQDs induced cellular autophagy to various degrees except for cGQDs. Further analysis on autophagy pathways indicated all GQDs significantly activated p-p38 MAPK; p-ERK1/2 was inhibited by aGQDs and hGQDs but activated by c GQDs. p-JNK was inhibited by aGQDs and c GQDs, while activated by hGQDs. Simultaneously, Akt was activated by hGQDs but inhibited by aGQDs. Inhibition of autophagy by 3-MA significantly increased the cytotoxicity of GQDs, suggesting that autophagy played a protective role against the toxicity of GQDs. In conclusion, c GQDs showed excellent biocompatibility and may be considered for biological applications. Autophagy induction may be included in the health risk assessment of GQDs as it reflects the stress status which may eventually lead to diseases.

关键词： Graphene quantum dots Cytotoxicity Autophagy Surface functional group