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Ghorbani Gorji S, Hawker DW, Mackie R, Higgins CP, Bowles K, Li Y, Kaserzon S. Sorption affinity and mechanisms of per-and polyfluoroalkyl substances (PFASs) with commercial sorbents: Implications for passive sampling. J Hazard Mater 2023; 457:131688. [PMID: 37257384 DOI: 10.1016/j.jhazmat.2023.131688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/17/2023] [Accepted: 05/22/2023] [Indexed: 06/02/2023]
Abstract
Effective monitoring tools, including passive samplers, are essential for the wide range of per- and polyfluoroalkyl substances (PFASs) in aquatic matrices. However, knowledge of the extent and mechanisms of PFASs sorption with sorbents in a passive sampling context is limited. To address this, sorption behavior of 45 anionic, neutral and zwitterionic PFASs ranging in perfluorocarbon chain length (C3-C16) and functional groups with 11 different commercial sorbents (cross-linked β-cyclodextrin polymers, activated carbon, anion exchange (AE), cation exchange, hydrophilic-lipophilic balanced (HLB) and non-polar) was investigated. A broad range of equilibrium sorbent-MilliQ water (MQ) distribution coefficients (Kd) were observed (10-1.95 to 108.30 mL g-1). Similar sorbent types (e.g., various AE and HLB sorbents) exhibited very different sorption behavior, likely due to their different polymeric structures and relative importance of sorbate/sorbent interactions other than coulombic interactions. HLB and AE with hydroxyl functionalities are most effective for sampling of the full suite of PFASs. Reduced sorptive affinity was observed in the presence of matrix co-constituents in wastewater influent for most PFASs. HLB had the smallest reduction in log Kd in wastewater suggesting that these sorbents are appropriate for applications in complex matrices. Sufficient sorbent capacity was observed for linear uptake of many target analytes which facilitates passive sampling.
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Affiliation(s)
- Sara Ghorbani Gorji
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia.
| | - Darryl W Hawker
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia; School of Environment and Science, Griffith University, Brisbane, Australia
| | - Rachel Mackie
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia
| | - Christopher P Higgins
- Department of Civil and Environmental Engineering, Colorado School of Mines, CO, United States
| | - Karl Bowles
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia; Jacobs, North Sydney, Australia
| | - Yan Li
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia
| | - Sarit Kaserzon
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia
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2
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Fabregat-Palau J, Yu Z, Zeng X, Vidal M, Rigol A. Deriving parametric and probabilistic K d values for fluoroquinolones in soils. Sci Total Environ 2023; 861:160266. [PMID: 36427719 DOI: 10.1016/j.scitotenv.2022.160266] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/14/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
The evaluation of the sorption affinity of fluoroquinolone antibiotics (FQs) in soils, by means of the derivation of solid-liquid distribution coefficients (Kd), is a valuable information for assessing their environmental mobility. Aiming to develop Kd (FQ) prediction tools in soils, in the first stage of this study we constructed a Kd (FQ) sorption dataset using current literature data. Furthermore, additional sorption and desorption data for norfloxacin were obtained in seven different soils of contrasting properties. Sorption isotherms of norfloxacin were linear under the experimental conditions tested and desorption percentages increased for scenarios in which low sorption was noted. Sorption tests in the same soils were then extended to ciprofloxacin, enrofloxacin and ofloxacin and pooled in the dataset, revealing comparable Kd (FQ) values among the FQ tested after analyzing the overall dataset consisting in 312 entries of Kd (FQ). A partial least square (PLS) regression model was then developed to predict values of Kd (FQ) based on specific relevant soil properties (i.e., pH, cation exchange capacity and organic carbon and texture information), and, for the first time, FQ properties (fraction of cationic FQ species) affecting sorption. Additionally, probabilistic, Kd (FQ) best estimates in soils were derived through cumulative distribution functions (CDFs) for the overall and for partial datasets created by grouping Kd (FQ) values according to key soil properties affecting FQ sorption (i.e., pH, organic carbon content and texture information). This latter approach permitted to derive more representative Kd (FQ) best estimates for the soils to be assessed, and with a lower related variability than that derived from the overall dataset. Best estimates Kd (FQ) values were > 1000 L kg-1 for most acidic to neutral soils, suggesting strong sorption, although lower sorption and thus higher environmental mobility may be expected in scenarios with soils with alkaline pH, low OC and high sand contents. SYNOPSIS: This study aims to derive parametric and probabilistic Kd values for fluoroquinolone antibiotics in soils on the basis of a few relevant soil physicochemical properties.
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Affiliation(s)
- Joel Fabregat-Palau
- Department of Chemical Engineering and Analytical Chemistry, Universitat de Barcelona (UB), Martí i Franquès 1-11, 08028 Barcelona, Spain; State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangdong 510640, People's Republic of China
| | - Zhiqiang Yu
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangdong 510640, People's Republic of China
| | - Xiangying Zeng
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, Guangdong 510640, People's Republic of China
| | - Miquel Vidal
- Department of Chemical Engineering and Analytical Chemistry, Universitat de Barcelona (UB), Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Anna Rigol
- Department of Chemical Engineering and Analytical Chemistry, Universitat de Barcelona (UB), Martí i Franquès 1-11, 08028 Barcelona, Spain; Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), Martí i Franquès 1-11, 08028 Barcelona, Spain.
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3
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Fabregat-Palau J, Vidal M, Rigol A. Modelling the sorption behaviour of perfluoroalkyl carboxylates and perfluoroalkane sulfonates in soils. Sci Total Environ 2021; 801:149343. [PMID: 34418616 DOI: 10.1016/j.scitotenv.2021.149343] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 06/13/2023]
Abstract
A simple parametric model was developed to predict the sorption of perfluoroalkyl substances (PFASs) in soils. Initially, sorption and desorption solid-liquid distribution coefficients (Kd and Kd,des respectively) of eight PFASs (five perfluoroalkyl carboxylates, PFCAs, and three perfluoroalkane sulfonates, PFSAs) in seven soils with organic carbon (OC) content ranging from 1.6 to 41% were quantified using batch experiments. The information obtained helped to fill the gaps in a literature-based database of Kd values of PFASs, which was lacking data on soils with high OC content. The overall dataset finally comprised 435 entries. Normalized sorption coefficients for the soil OC and mineral fraction contents (KOC and KMIN respectively) were deduced for each PFAS by correlating the corresponding Kd values obtained under a wide range of experimental conditions with the fraction of organic carbon (fOC) of the soils. Furthermore, the sorption mechanisms in each phase were shown to depend mainly on PFAS chain length. The dependence of KOC and KMIN values on PFAS chain length defined the basic equations to construct the model for predicting PFAS sorption, applicable to both PFCAs and PFSAs with chain lengths ranging from 3 to 11 fluorinated carbons. The validation of the proposed model confirmed its ability to predict the Kd of PFASs based only on the soil OC and silt+clay contents and PFAS chain length. Therefore, it can be used in the first stages of a risk assessment process aiming at estimating the potential mobility of PFASs in soils after a contamination event. SYNOPSIS: This study develops a new parametric model to predict the sorption of perfluoroalkyl substances (PFASs) in soils.
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Affiliation(s)
- Joel Fabregat-Palau
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Miquel Vidal
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Anna Rigol
- Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
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4
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Bam W, Teyssié JL, Metian M, Oberhaensli F, Maiti K, Swarzenski PW. An experimental approach to assess the post-depositional mobility of 134Cs. J Environ Radioact 2021; 240:106753. [PMID: 34619634 DOI: 10.1016/j.jenvrad.2021.106753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 09/17/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
The partitioning coefficient, Kd, which is defined by the reversible sorption processes between a solid and an aqueous phase at equilibrium, is one of the most important parameters to assess environmental transport and risk. In this study, a series of simple laboratory experiments were conducted to investigate sorption properties of 134Cs on a model sediment under two treatments (shaken vs non-shaken) and with three (small: <75 μm, large: > 75 μm and bulk i.e., composite) particle size fractions. Vertical transport of 134Cs across the water-sediment interface and into sediment was also evaluated. As expected, grain size had the strongest influence on 134Cs Kd values, with the small particle size fraction yielding significantly higher Kd values than the large and bulk fractions. The mean Kd values obtained from the various experiments ranged from 89 ± 13-130 ± 5 L kg-1 (small), 44 ± 10-91 ± 13 L kg-1 (large), 73 ± 3-112 ± 11 L kg-1 (bulk, shaken) and 73 ± 5-110 ± 4 L kg-1 (bulk, non-shaken). Most of the 134Cs partitioning processes occurred rapidly (<2 h) into the experiment. Physical mixing (shaken) did not appear to significantly affect the 134Cs Kd values. In complement, a separate experiment on the vertical penetration of 134Cs into a bulk sediment column showed that 134Cs was able to penetrate up to 5 cm into the sediment column after 88 days (∼0.6 mm d-1) and this flux rate is comparable to natural settings. Adsorption and contact time were found to be key for the 134Cs penetration process. Results from these experiments add to the literature on post-event radionuclide transport studies in marine settings and provide an experimental perspective that can be built upon to complement field observations.
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Affiliation(s)
- Wokil Bam
- International Atomic Energy Agency, Principality of Monaco, 98000, Monaco; Department Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA; Department of Marine Chemistry and Geochemisty, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
| | - Jean-Louis Teyssié
- International Atomic Energy Agency, Principality of Monaco, 98000, Monaco
| | - Marc Metian
- International Atomic Energy Agency, Principality of Monaco, 98000, Monaco
| | | | - Kanchan Maiti
- Department Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Peter W Swarzenski
- International Atomic Energy Agency, Principality of Monaco, 98000, Monaco.
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Kazakevičiūtė-Jakučiūnienė L, Druteikienė R, Maceika E, Lukšienė B, Juškėnas R, Pakštas V, Žukauskaitė Z, Gvozdaitė R, Tarasiuk N. Impact of soil organic matter on Pu migration in five Lithuanian surface soils. J Environ Radioact 2021; 237:106702. [PMID: 34284309 DOI: 10.1016/j.jenvrad.2021.106702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 06/28/2021] [Accepted: 07/10/2021] [Indexed: 06/13/2023]
Abstract
Pu distribution coefficient Kd variation was experimentally determined and examined in natural soil samples considering the type of soil, particle size, pH, the concentration of macroelements and organic matter content. This research was carried out with sand, silty sand, peat, clayey sand and clayey loam samples by applying 236Pu tracer in flow-through column tests. Due to relatively short contact time of 0.5-40 h the tests are considered as have not reached equilibrium state and represent the fast-moving contaminants retardation processes closer to field conditions. Every soil sample was fractionated into two particle size fractions: ≤0.25 mm and 0.25 ÷ 0.5 mm. Analysis revealed that Kd of Pu is higher for the smaller soil particle fraction (≤0.25 mm). The experimental study with 1.6, 4, 6 and 9 pH tracer solution revealed a tendency of elevated Kd when 4 pH and 6 pH solutions were applied, but obtained Kd values were not correlated with initial soil pH due to high buffering capacity of soils. This study shows a very significant influence (r = 0.98) of organic matter content on the Pu distribution coefficient. The Kd of Pu for the fine fraction of peat soil with high organic matter content (67%) reached maximum values of 6597 L/kg and 6200 L/kg when tracer solution was applied of pH = 4 and pH = 6, respectively. In comparison, the minimum Kd value of 3.9 L/kg was obtained for the coarse silty sand fraction with the lowest organic matter content of 1.3% at tracer pH = 1.6. A statistically reliable high correlations of r = 0.95 and 0.94 were also observed between Kd and specific soil elements Mg and Pb content in soils, respectively. The content of Fe in soils was significantly correlated (r = 0.67) with the Kd values of plutonium as well. However, the organic matter content in soils appeared to be the governing factor determining good correlations and causing the highest Kd of Pu values.
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Affiliation(s)
| | - Rūta Druteikienė
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Evaldas Maceika
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania.
| | - Benedikta Lukšienė
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Remigijus Juškėnas
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Vidas Pakštas
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Zita Žukauskaitė
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Rasa Gvozdaitė
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
| | - Nikolaj Tarasiuk
- State Research Institute Center for Physical and Technological Sciences, Savanoriu av. 231, LT-02300, Vilnius, Lithuania
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6
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P C. A comprehensive probabilistic approach for integrating and separating natural variability and parametric uncertainty in the prediction of distribution coefficient of radionuclides in rivers. J Environ Radioact 2020; 225:106371. [PMID: 32978004 DOI: 10.1016/j.jenvrad.2020.106371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 07/24/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
A geochemical speciation model was developed to predict Distribution coefficients (Kds) of radionuclides (RNs) in rivers. The model takes into account complexation of RNs with inorganic ligands, sorption of RNs with hydrous ferric oxides, complexation of RNs with dissolved and particulate organic carbon (DOC and POC) and sorption and/or co-precipitation of RNs to carbonates. A sorption model of Cs onto clay was also integrated. The tool is also designed to conduct uncertainty and sensitivity analysis. Sensitivity analysis follows a stepwise structured approach, starting from computationally 'inexpensive' Morris method to most costly variance-based EFAST method. A nested Monte Carlo approach was also implemented to separate natural variability and lack of knowledge in global uncertainty assessment. As case studies, Kd distributions were estimated for Co, Mn, Ag and Cs in seven French rivers. Uncertainty analysis allowed to quantify Kd ranges that can be expected when considering all the sensitive parameters together.
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Affiliation(s)
- Ciffroy P
- EDF, Division Recherche et Développement, Laboratoire National d'Hydraulique et Environnement, 6 quai Watier, 78401, Chatou, France.
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7
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Johansen MP, Cresswell T, Davis J, Howard DL, Howell NR, Prentice E. Biofilm-enhanced adsorption of strong and weak cations onto different microplastic sample types: Use of spectroscopy, microscopy and radiotracer methods. Water Res 2019; 158:392-400. [PMID: 31059933 DOI: 10.1016/j.watres.2019.04.029] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 03/29/2019] [Accepted: 04/13/2019] [Indexed: 06/09/2023]
Abstract
The adsorption of metals and other elements onto environmental plastics has been previously quantified and is known to be enhanced by surface-weathering and development of biofilms. However, further biofilm-adsorption characterisation is needed with respect to the fate of radionuclides. This study uses spectroscopy, microscopy and radiotracer methods to investigate the adsorption capacity of relatively strong and weak cations onto different microplastic sample types that were conditioned in freshwater, estuarine and marine conditions although marine data were limited. Fourier-transform infrared spectroscopy confirmed that surface oxidation chemistry changes induced by gamma irradiation were similar to those resulting from environmental exposures. Microscopy elemental mapping revealed patchy biofilm development, which contained Si, Al, and O, consistent with microbial-facilitated capture of clays. The plastics+biofilm of all sample types had measurable adsorption for Cs and Sr radiotracers, suggesting environmental plastics act broadly as a sink for the key pervasive environmental radionuclides of 137Cs and 90Sr associated with releases from nuclear activities. Adsorption onto high-density polyethylene plastic types was greater than that on polypropylene. However, in most cases, the adsorption rates of all types of plastic+biofilm were much lower than those of reference sediments and roughly consistent with their relative exchangeable surface areas.
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Affiliation(s)
- Mathew P Johansen
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | - Tom Cresswell
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Joel Davis
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Daryl L Howard
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria, 3168, Australia
| | - Nicholas R Howell
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Emily Prentice
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia; University of Technology Sydney, 15 Broadway, Ultimo, NSW, 2007, Australia
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8
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Johansen MP, Prentice E, Cresswell T, Howell N. Initial data on adsorption of Cs and Sr to the surfaces of microplastics with biofilm. J Environ Radioact 2018; 190-191:130-133. [PMID: 29787932 DOI: 10.1016/j.jenvrad.2018.05.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 05/20/2023]
Abstract
The adsorption of radiocesium and radiostrontium onto a range of natural materials has been well quantified, but not for the new media of environmental plastics, which may have enhanced adsorption due to surface-weathering and development of biofilms. Microplastic samples were deployed in freshwater, estuarine and marine conditions, then characterised using infrared spectroscopy to document changes to the plastic surface (vs interior). Synchrotron elemental mapping data revealed surfaces that were well-covered by accumulation of reactive water solutes and sulphur, but, in contrast, had highly discrete coverage of elements such as Fe and Ti, indicating adhered mineral/clay-associated agglomerates that may increase overall adsorption capacity. Plastics that had been deployed for nearly five months adsorbed radionuclides in both freshwater and estuarine conditions with the highest Kd for cesium (Cs) in freshwater (80 ml g-1) and lowest for strontium (Sr) in estuarine conditions (5 ml g-1). The degree of Cs and Sr adsorption onto plastics appears to be approximately 2-3 orders of magnitude lower than for sediment reference values. While lower than for sediments, adsorption occurred on all samples and may indicate a significant radionuclide reservoir, given that plastics are relatively buoyant and mobile in water regimes, and are increasing in global aquatic systems.
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Affiliation(s)
- Mathew P Johansen
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia.
| | - Emily Prentice
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia; University of Technology Sydney, 15 Broadway, Ultimo, NSW, 2007, Australia
| | - Tom Cresswell
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
| | - Nick Howell
- Australian Nuclear Science and Technology Organisation (ANSTO), Locked Bag 2001, Kirrawee DC, NSW, 2232, Australia
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9
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Abstract
Determining the equilibrium-binding affinity (Kd) of two interacting proteins is essential not only for the biochemical study of protein signaling and function but also for the engineering of improved protein and enzyme variants. One common technique for measuring protein-binding affinities uses flow cytometry to analyze ligand binding to proteins presented on the surface of a cell. However, cell-binding assays require specific considerations to accurately quantify the binding affinity of a protein-protein interaction. Here we will cover the basic assumptions in designing a cell-based binding assay, including the relevant equations and theory behind determining binding affinities. Further, two major considerations in measuring binding affinities-time to equilibrium and ligand depletion-will be discussed. As these conditions have the potential to greatly alter the Kd, methods through which to avoid or minimize them will be provided. We then outline detailed protocols for performing direct- and competitive-binding assays against proteins displayed on the surface of yeast or mammalian cells that can be used to derive accurate Kd values. Finally, a comparison of cell-based binding assays to other types of binding assays will be presented.
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Affiliation(s)
- S A Hunter
- Stanford University, Stanford, CA, United States
| | - J R Cochran
- Stanford University, Stanford, CA, United States.
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10
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Ozaki H, Katoh T, Nakagawa R, Ishihara Y, Sueyoshi N, Kameshita I, Taniguchi T, Hirano T, Yamazaki T, Ishida A. Ca(2+)/calmodulin-dependent protein kinase phosphatase (CaMKP/PPM1F) interacts with neurofilament L and inhibits its filament association. Biochem Biophys Res Commun 2016; 477:820-825. [PMID: 27369073 DOI: 10.1016/j.bbrc.2016.06.141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 06/27/2016] [Indexed: 01/24/2023]
Abstract
Ca(2+)/calmodulin-dependent protein kinase phosphatase (CaMKP/PPM1F) is a Ser/Thr phosphatase that belongs to the PPM family. Growing evidence suggests that PPM phosphatases including CaMKP act as a complex with other proteins to regulate cellular functions. In this study, using the two-dimensional far-western blotting technique with digoxigenin-labeled CaMKP as a probe, in conjunction with peptide mass fingerprinting analysis, we identified neurofilament L (NFL) as a CaMKP-binding protein in a Triton-insoluble fraction of rat brain. We confirmed binding of fluorescein-labeled CaMKP (F-CaMKP) to NFL in solution by fluorescence polarization. The analysis showed that the dissociation constant of F-CaMKP for NFL is 73 ± 17 nM (n = 3). Co-immunoprecipitation assay using a cytosolic fraction of NGF-differentiated PC12 cells showed that endogenous CaMKP and NFL form a complex in cells. Furthermore, the effect of CaMKP on self-assembly of NFL was examined. Electron microscopy revealed that CaMKP markedly prevented NFL from forming large filamentous aggregates, suggesting that CaMKP-binding to NFL inhibits its filament association. These findings may provide new insights into a novel mechanism for regulating network formation of neurofilaments during neuronal differentiation.
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Affiliation(s)
- Hana Ozaki
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521, Japan
| | - Tsuyoshi Katoh
- Department of Biochemistry, Asahikawa Medical University, Asahikawa, 078-8510, Japan
| | - Ryoko Nakagawa
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521, Japan
| | - Yasuhiro Ishihara
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521, Japan
| | - Noriyuki Sueyoshi
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Isamu Kameshita
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Takanobu Taniguchi
- Department of Biochemistry, Asahikawa Medical University, Asahikawa, 078-8510, Japan
| | - Tetsuo Hirano
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521, Japan
| | - Takeshi Yamazaki
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521, Japan
| | - Atsuhiko Ishida
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521, Japan.
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11
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Quang NN, Pestourie C, Cibiel A, Ducongé F. How to measure the affinity of aptamers for membrane proteins expressed on the surface of living adherent cells. Methods 2015; 97:35-43. [PMID: 26589188 DOI: 10.1016/j.ymeth.2015.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/10/2015] [Indexed: 02/07/2023] Open
Abstract
Recently, an increasing number of aptamers have been selected against biomarkers that are expressed at the surface of cells. This class of targets, mostly membrane proteins, is in close contact with the intra- and extra-cellular matrixes and their three-dimensional structures are inextricably linked to their inclusion in lipid bilayers. Therefore, although binding studies can be performed on the isolated form of these proteins, it remains crucial to measure the affinity of these aptamers in a more physiological environment, i.e., directly on living cells. Here, we describe a procedure for radioactive binding assays that can be adapted for measuring the affinity of aptamers against different cell lines. This method has been semi-automated using a liquid handling robot in order to reproducibly measure the apparent dissociation constant Kd and the apparent number of targets per cell. Relevant issues are discussed including the labeling of aptamers, the cells preparation, the incubation, the washings, the use of non-specific competitors, the data analysis and finally the reporting.
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Affiliation(s)
- Nam Nguyen Quang
- CEA, DSV, I2BM, Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Université Paris-Sud, UMR 9199, Fontenay-aux-Roses, France
| | - Carine Pestourie
- Inserm, UMS006/CREFRE, Service Exploration Non-Invasive, Toulouse, France; Université Fédérale Toulouse Midi-Pyrénées, Université Toulouse III-Paul Sabatier, UMS006/CREFRE, Toulouse, France
| | | | - Frédéric Ducongé
- CEA, DSV, I2BM, Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France; Neurodegenerative Diseases Laboratory, Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Université Paris-Sud, UMR 9199, Fontenay-aux-Roses, France.
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12
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Domènech C, García D, Pękala M. Decreasing Kd uncertainties through the application of thermodynamic sorption models. Sci Total Environ 2015; 527-528:297-305. [PMID: 25965043 DOI: 10.1016/j.scitotenv.2015.04.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 04/21/2015] [Accepted: 04/25/2015] [Indexed: 06/04/2023]
Abstract
Radionuclide retardation processes during transport are expected to play an important role in the safety assessment of subsurface disposal facilities for radioactive waste. The linear distribution coefficient (Kd) is often used to represent radionuclide retention, because analytical solutions to the classic advection-diffusion-retardation equation under simple boundary conditions are readily obtainable, and because numerical implementation of this approach is relatively straightforward. For these reasons, the Kd approach lends itself to probabilistic calculations required by Performance Assessment (PA) calculations. However, it is widely recognised that Kd values derived from laboratory experiments generally have a narrow field of validity, and that the uncertainty of the Kd outside this field increases significantly. Mechanistic multicomponent geochemical simulators can be used to calculate Kd values under a wide range of conditions. This approach is powerful and flexible, but requires expert knowledge on the part of the user. The work presented in this paper aims to develop a simplified approach of estimating Kd values whose level of accuracy would be comparable with those obtained by fully-fledged geochemical simulators. The proposed approach consists of deriving simplified algebraic expressions by combining relevant mass action equations. This approach was applied to three distinct geochemical systems involving surface complexation and ion-exchange processes. Within bounds imposed by model simplifications, the presented approach allows radionuclide Kd values to be estimated as a function of key system-controlling parameters, such as the pH and mineralogy. This approach could be used by PA professionals to assess the impact of key geochemical parameters on the variability of radionuclide Kd values. Moreover, the presented approach could be relatively easily implemented in existing codes to represent the influence of temporal and spatial changes in geochemistry on Kd values.
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Affiliation(s)
| | - David García
- Amphos 21, Passeig de Garcia i Fària 49-51, 08019, Barcelona, Spain.
| | - Marek Pękala
- Amphos 21, Passeig de Garcia i Fària 49-51, 08019, Barcelona, Spain
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13
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Liu B, Zhang H, Xie L, Li J, Wang X, Zhao L, Wang Y, Yang B. Spatial distribution and partition of perfluoroalkyl acids (PFAAs) in rivers of the Pearl River Delta, southern China. Sci Total Environ 2015; 524-525:1-7. [PMID: 25889539 DOI: 10.1016/j.scitotenv.2015.04.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 04/01/2015] [Accepted: 04/01/2015] [Indexed: 06/04/2023]
Abstract
This study investigated the occurrence of perfluoroalkyl acids (PFAAs) in surface water from 67 sampling sites along rivers of the Pearl River Delta in southern China. Sixteen PFAAs, including perfluoroalkyl carboxylic acids (PFCAs, C5-14, C16 and C18) and perfluoroalkyl sulfonic acids (PFSAs, C4, C6, C8 and C10) were determined by high performance liquid chromatography-negative electrospray ionization-tandem mass spectrometry (HPLC/ESI-MS/MS). Total PFAA concentrations (∑ PFAAs) in the surface water ranged from 1.53 to 33.5 ng·L(-1) with an average of 7.58 ng·L(-1). Perfluorobutane sulfonic acid (PFBS), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS) were the three most abundant PFAAs and on average accounted for 28%, 16% and 10% of ∑ PFAAs, respectively. Higher concentrations of ∑ PFAAs were found in the samples collected from Jiangmen section of Xijiang River, Dongguan section of Dongjiang River and the Pearl River flowing the cities which had very well-developed manufacturing industries. PCA model was employed to quantitatively calculate the contributions of extracted sources. Factor 1 (72.48% of the total variance) had high loading for perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), PFBS and PFOS. For factor 2 (10.93% of the total variance), perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUdA) got high loading. The sorption of PFCAs on suspended particulate matter (SPM) increased by approximately 0.1 log units for each additional CF2 moiety and that on sediment was approximately 0.8 log units lower than the SPM logKd values. In addition, the differences in the partition coefficients were influenced by the structure discrepancy of absorbents and influx of fresh river water. These data are essential for modeling the transport and environmental fate of PFAAs.
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Affiliation(s)
- Baolin Liu
- College of Physical Science and Technology, Shenzhen University, Shenzhen 518060, China; College of Chemistry, Changchun Normal University, Changchun 130032, China; College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300222, China
| | - Hong Zhang
- College of Physical Science and Technology, Shenzhen University, Shenzhen 518060, China.
| | - Liuwei Xie
- College of Physical Science and Technology, Shenzhen University, Shenzhen 518060, China
| | - Juying Li
- College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xinxuan Wang
- College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300222, China
| | - Liang Zhao
- College of Physical Science and Technology, Shenzhen University, Shenzhen 518060, China
| | - Yanping Wang
- College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300222, China
| | - Bo Yang
- College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, China
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14
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Maity S, Pandit GG. Estimation of Kd of lead and (210)Po in 11 soils from India. J Environ Radioact 2014; 138:434-437. [PMID: 24787466 DOI: 10.1016/j.jenvrad.2014.03.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 03/18/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
The fate of contaminant transport is often estimated using the distribution (partition) coefficient, Kd. It is a measure of sorption of contaminants to soil. As Kd is element, soil type and ground water dependent, chemical characterization of soil and ground water of the particular site is essential. In this study, soil and ground water samples from different locations around India were collected. The soil samples were physically characterized and pH, CaCO3, cation exchange capacity (CEC), organic matter and organic carbon were determined. Equilibration time for lead and (210)Po were estimated with respect to contact time and were found to be 28 and 72 h respectively. The Kd of lead varied from 6700 to 31,000 L/kg with a geometric mean of 15,200 L/kg, and for (210)Po from 1400 to 8700 L/kg with a geometric mean of 3700 L/kg.
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Affiliation(s)
- Sukanta Maity
- Environmental Monitoring & Assessment Section, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - G G Pandit
- Environmental Monitoring & Assessment Section, Bhabha Atomic Research Centre, Mumbai 400085, India.
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15
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Han L, Zhao Y, Zhang X, Peng J, Xu P, Huan S, Zhang M. RFP tags for labeling secretory pathway proteins. Biochem Biophys Res Commun 2014; 447:508-12. [PMID: 24732352 DOI: 10.1016/j.bbrc.2014.04.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 04/06/2014] [Indexed: 11/26/2022]
Abstract
Red fluorescent proteins (RFPs) are useful tools for live cell and multi-color imaging in biological studies. However, when labeling proteins in secretory pathway, many RFPs are prone to form artificial puncta, which may severely impede their further uses. Here we report a fast and easy method to evaluate RFPs fusion properties by attaching RFPs to an environment sensitive membrane protein Orai1. In addition, we revealed that intracellular artificial puncta are actually colocalized with lysosome, thus besides monomeric properties, pKa value of RFPs is also a key factor for forming intracellular artificial puncta. In summary, our current study provides a useful guide for choosing appropriate RFP for labeling secretory membrane proteins. Among RFPs tested, mOrange2 is highly recommended based on excellent monomeric property, appropriate pKa and high brightness.
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Affiliation(s)
- Liyang Han
- State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Yanhua Zhao
- State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Xi Zhang
- College of Life Sciences, Central China Normal University, Wuhan 430079, Hubei, China
| | - Jianxin Peng
- College of Life Sciences, Central China Normal University, Wuhan 430079, Hubei, China
| | - Pingyong Xu
- Key Laboratory of Interdisciplinary Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Shuangyan Huan
- State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
| | - Mingshu Zhang
- Key Laboratory of Interdisciplinary Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
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16
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Luo Y, Guo W, Ngo HH, Nghiem LD, Hai FI, Zhang J, Liang S, Wang XC. A review on the occurrence of micropollutants in the aquatic environment and their fate and removal during wastewater treatment. Sci Total Environ 2014; 473-474:619-41. [PMID: 24394371 DOI: 10.1016/j.scitotenv.2013.12.065] [Citation(s) in RCA: 1687] [Impact Index Per Article: 168.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/17/2013] [Accepted: 12/17/2013] [Indexed: 05/20/2023]
Abstract
Micropollutants are emerging as a new challenge to the scientific community. This review provides a summary of the recent occurrence of micropollutants in the aquatic environment including sewage, surface water, groundwater and drinking water. The discharge of treated effluent from WWTPs is a major pathway for the introduction of micropollutants to surface water. WWTPs act as primary barriers against the spread of micropollutants. WWTP removal efficiency of the selected micropollutants in 14 countries/regions depicts compound-specific variation in removal, ranging from 12.5 to 100%. Advanced treatment processes, such as activated carbon adsorption, advanced oxidation processes, nanofiltration, reverse osmosis, and membrane bioreactors can achieve higher and more consistent micropollutant removal. However, regardless of what technology is employed, the removal of micropollutants depends on physico-chemical properties of micropollutants and treatment conditions. The evaluation of micropollutant removal from municipal wastewater should cover a series of aspects from sources to end uses. After the release of micropollutants, a better understanding and modeling of their fate in surface water is essential for effectively predicting their impacts on the receiving environment.
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Affiliation(s)
- Yunlong Luo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Wenshan Guo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
| | - Huu Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
| | - Long Duc Nghiem
- Strategic Water Infrastructure Laboratory, School of Civil Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Faisal Ibney Hai
- Strategic Water Infrastructure Laboratory, School of Civil Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Jian Zhang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China
| | - Shuang Liang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China
| | - Xiaochang C Wang
- Key Lab of Northwest Water Resources, Environment and Ecology, Ministry of Education, Xi'an University of Architecture and Technology, Xi'an 710055, China
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17
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Vonberg D, Vanderborght J, Cremer N, Pütz T, Herbst M, Vereecken H. 20 years of long-term atrazine monitoring in a shallow aquifer in western Germany. Water Res 2014; 50:294-306. [PMID: 24188580 DOI: 10.1016/j.watres.2013.10.032] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 09/06/2013] [Accepted: 10/14/2013] [Indexed: 05/25/2023]
Abstract
Atrazine was banned in Germany in 1991 due to findings of atrazine concentrations in ground- and drinking waters exceeding threshold values. Monitoring of atrazine concentrations in the groundwater since then provides information about the resilience of the groundwater quality to changing agricultural practices. In this study, we present results of a monitoring campaign of atrazine concentrations in the Zwischenscholle aquifer. This phreatic aquifer is exposed to intensive agricultural land use and susceptible to contaminants due to a shallow water table. In total 60 observation wells (OWs) have been monitored since 1991, of which 15 are sampled monthly today. Descriptive statistics of monitoring data were derived using the "regression on order statistics" (ROS) data censoring approach, estimating values for nondetects. The monitoring data shows that even 20 years after the ban of atrazine, the groundwater concentrations of sampled OWs remain on a level close to the threshold value of 0.1 μg l(-1) without any considerable decrease. The spatial distribution of atrazine concentrations is highly heterogeneous with OWs exhibiting permanently concentrations above the regulatory threshold on the one hand and OWs were concentrations are mostly below the limit of quantification (LOQ) on the other hand. A deethylatrazine-to-atrazine ratio (DAR) was used to distinguish between diffuse - and point-source contamination, with a global mean value of 0.84 indicating mainly diffuse contamination. Principle Component Analysis (PCA) of the monitoring dataset demonstrated relationships between the metabolite desisopropylatrazine, which was found to be exclusively associated with the parent compound simazine but not with atrazine, and between deethylatrazine, atrazine, nitrate, and the specific electrical conductivity. These parameters indicate agricultural impacts on groundwater quality. The findings presented in this study point at the difficulty to estimate mean concentrations of contamination for entire aquifers and to evaluate groundwater quality based on average parameters. However, analytical data of monthly sampled single observation wells provide adequate information to characterize local contamination and evolutionary trends of pollutant concentration.
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Affiliation(s)
- David Vonberg
- Agrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
| | - Jan Vanderborght
- Agrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
| | - Nils Cremer
- Erftverband, Am Erftverband 6, 50126 Bergheim, Germany.
| | - Thomas Pütz
- Agrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
| | - Michael Herbst
- Agrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
| | - Harry Vereecken
- Agrosphere Institute (IBG-3), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
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18
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Gamage IH, Jonker A, Zhang X, Yu P. Non-destructive analysis of the conformational differences among feedstock sources and their corresponding co-products from bioethanol production with molecular spectroscopy. Spectrochim Acta A Mol Biomol Spectrosc 2014; 118:407-421. [PMID: 24076457 DOI: 10.1016/j.saa.2013.08.095] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2013] [Revised: 08/15/2013] [Accepted: 08/23/2013] [Indexed: 06/02/2023]
Abstract
The objective of this study was to determine the possibility of using molecular spectroscopy with multivariate technique as a fast method to detect the source effects among original feedstock sources of wheat and their corresponding co-products, wheat DDGS, from bioethanol production. Different sources of the bioethanol feedstock and their corresponding bioethanol co-products, three samples per source, were collected from the same newly-built bioethanol plant with current bioethanol processing technology. Multivariate molecular spectral analyses were carried out using agglomerative hierarchical cluster analysis (AHCA) and principal component analysis (PCA). The molecular spectral data of different feedstock sources and their corresponding co-products were compared at four different regions of ca. 1800-1725 cm(-1) (carbonyl CO ester, mainly related to lipid structure conformation), ca. 1725-1482 cm(-1) (amide I and amide II region mainly related to protein structure conformation), ca. 1482-1180 cm(-1) (mainly associated with structural carbohydrate) and ca. 1180-800 cm(-1) (mainly related to carbohydrates) in complex plant-based system. The results showed that the molecular spectroscopy with multivariate technique could reveal the structural differences among the bioethanol feedstock sources and among their corresponding co-products. The AHCA and PCA analyses were able to distinguish the molecular structure differences associated with chemical functional groups among the different sources of the feedstock and their corresponding co-products. The molecular spectral differences indicated the differences in functional, biomolecular and biopolymer groups which were confirmed by wet chemical analysis. These biomolecular and biopolymer structural differences were associated with chemical and nutrient profiles and nutrient utilization and availability. Molecular spectral analyses had the potential to identify molecular structure difference among bioethanol feedstock sources and their corresponding co-products.
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Affiliation(s)
- I H Gamage
- Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8, Canada
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19
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Filchenkov GN, Popoff EH, Naumov AD. The low dose gamma ionising radiation impact upon cooperativity of androgen-specific proteins. J Environ Radioact 2014; 127:182-190. [PMID: 23465891 DOI: 10.1016/j.jenvrad.2013.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 01/23/2013] [Accepted: 02/10/2013] [Indexed: 06/01/2023]
Abstract
The paper deals with effects of the ionising radiation (γ-IR, 0.5 Gy) upon serum testosterone (T), characteristics of testosterone-binding globulin (TeBG) and androgen receptor (AR) in parallel with observation of androgen (A) responsive enzyme activity - hexokinase (HK). The interdependence or relationships of T-levels with parameters of the proteins that provide androgenic regulation are consequently analyzed in post-IR dynamics. The IR-stress adjustment data reveal expediency of TeBG- and AR-cooperativity measurements for more precise assessments of endocrine A-control at appropriate emergencies.
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Affiliation(s)
- Gennady N Filchenkov
- Lab. of Biochemistry, Institute of Radiobiology, National Academy of Sciences of Belarus, Feduninskogo 4, Gomel 246007, Belarus
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20
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Del Cadia M, De Rienzo F, Weston DA, Thompson AJ, Menziani MC, Lummis SC. Exploring a potential palonosetron allosteric binding site in the 5-HT(3) receptor. Bioorg Med Chem 2013; 21:7523-8. [PMID: 24128813 PMCID: PMC3898987 DOI: 10.1016/j.bmc.2013.09.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 09/10/2013] [Accepted: 09/11/2013] [Indexed: 11/26/2022]
Abstract
Palonosetron (Aloxi) is a potent second generation 5-HT(3) receptor antagonist whose mechanism of action is not yet fully understood. Palonosetron acts at the 5-HT(3) receptor binding site but recent computational studies indicated other possible sites of action in the extracellular domain. To test this hypothesis we mutated a series of residues in the 5-HT3A receptor subunit (Tyr(73), Phe(130), Ser(163), and Asp(165)) and in the 5-HT3B receptor subunit (His(73), Phe(130), Glu(170), and Tyr(143)) that were previously predicted by in silico docking studies to interact with palonosetron. Homomeric (5-HT(3)A) and heteromeric (5-HT(3)AB) receptors were then expressed in HEK293 cells to determine the potency of palonosetron using both fluorimetric and radioligand methods to test function and ligand binding, respectively. The data show that the substitutions have little or no effect on palonosetron inhibition of 5-HT-evoked responses or binding. In contrast, substitutions in the orthosteric binding site abolish palonosetron binding. Overall, the data support a binding site for palonosetron at the classic orthosteric binding pocket between two 5-HT3A receptor subunits but not at allosteric sites previously identified by in silico modelling and docking.
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Affiliation(s)
- Marta Del Cadia
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
| | - Francesca De Rienzo
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
| | - David A. Weston
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Andrew J. Thompson
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
| | - Maria Cristina Menziani
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
| | - Sarah C.R. Lummis
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Via Campi 183, 41100 Modena, Italy
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK
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21
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Sanchez EJ, Hayes RP, Barr JT, Lewis KM, Webb BN, Subramanian AK, Nissen MS, Jones JP, Shelden EA, Sorg BA, Fill M, Schenk JO, Kang C. Potential role of cardiac calsequestrin in the lethal arrhythmic effects of cocaine. Drug Alcohol Depend 2013; 133:344-51. [PMID: 23876860 DOI: 10.1016/j.drugalcdep.2013.06.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Revised: 06/11/2013] [Accepted: 06/14/2013] [Indexed: 11/24/2022]
Abstract
BACKGROUND Cocaine-related deaths are continuously rising and its overdose is often associated with lethal cardiotoxic effects. METHODS AND RESULTS Our approach, employing isothermal titration calorimetry (ITC) and light scattering in parallel, has confirmed the significant affinity of human cardiac calsequestrin (CASQ2) for cocaine. Calsequestrin (CASQ) is a major Ca(2+)-storage protein within the sarcoplasmic reticulum (SR) of both cardiac and skeletal muscles. CASQ acts as a Ca(2+) buffer and Ca(2+)-channel regulator through its unique Ca(2+)-dependent oligomerization. Equilibrium dialysis and atomic absorption spectroscopy experiments illustrated the perturbational effect of cocaine on CASQ2 polymerization, resulting in substantial reduction of its Ca(2+)-binding capacity. We also confirmed the accumulation of cocaine in rat heart tissue and the substantial effects cocaine has on cultured C2C12 cells. The same experiments were performed with methamphetamine as a control, which displayed neither affinity for CASQ2 nor any significant effects on its function. Since cocaine did not have any direct effect on the Ca(2+)-release channel judging from our single channel recordings, these studies provide new insights into how cocaine may interfere with the normal E-C coupling mechanism with lethal arrhythmogenic consequences. CONCLUSION We propose that cocaine accumulates in SR through its affinity for CASQ2 and affects both SR Ca(2+) storage and release by altering the normal CASQ2 Ca(2+)-dependent polymerization. By this mechanism, cocaine use could produce serious cardiac problems, especially in people who have genetically-impaired CASQ2, defects in other E-C coupling components, or compromised cocaine metabolism and clearance.
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Fernández-Bayo JD, Saison C, Voltz M, Disko U, Hofmann D, Berns AE. Chlordecone fate and mineralisation in a tropical soil (andosol) microcosm under aerobic conditions. Sci Total Environ 2013; 463-464:395-403. [PMID: 23827360 DOI: 10.1016/j.scitotenv.2013.06.044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 05/27/2013] [Accepted: 06/10/2013] [Indexed: 06/02/2023]
Abstract
Chlordecone is a persistent organochlorine insecticide that, even decades after its ban, poses a threat to the environment and human health. Nevertheless, its environmental fate in soils has scarcely been investigated, and elementary data on its degradation and behaviour in soil are lacking. The mineralisation and sorption of chlordecone and the formation of possible metabolites were evaluated in a tropical agricultural andosol. Soil microcosms with two different soil horizons (S-A and S-B) were incubated for 215 days with 14C-chlordecone. At five different times (1, 33, 88, 150 and 215 days) the extractability of 14C-chlordecone was analysed. Mineralisation was monitored using 14CO2 traps of NaOH. The appearance of metabolites was studied using thin layer and gas chromatography techniques. At the end of the experiment, the water soluble 14C-activity was 2% of the remaining 14C-chlordecone for S-A and 8% for S-B. Only 12% of the remaining activity was non extractable and more than 80% remained extractable with organic solvents. For the first time to our knowledge, a significant mineralisation of chlordecone was measured in a microcosm under aerobic conditions (4.9% for S-A and 3.2% for S-B of the initial 14C-activity). The drastically lower emission of 14CO2 in sterilised microcosms indicated the biological origin of chlordecone mineralisation in the non-sterilised microcosms. No metabolites could be detected in the soil extracts. The mineralisation rate of chlordecone decreased by one order of magnitude throughout the incubation period. Thus, the chlordecone content in the soil remained large. This study confirms the existence of chlordecone degrading organisms in a tropical andosol. The reasons why their activity is restricted should be elucidated to allow the development of bioremediation approaches. Possible reasons are a heterogeneous distribution a chlordecone between sub-compartments with different microbial activities or a degradation of chlordecone by co-metabolic processes controlled by a limited supply of nutrients.
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Affiliation(s)
- Jesus D Fernández-Bayo
- IRD, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1, France; INRA, UMR LISAH Bât 24, 2 Place Viala, 34060 Montpellier cedex 1, France.
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23
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Hamid H, Eskicioglu C. Effect of microwave hydrolysis on transformation of steroidal hormones during anaerobic digestion of municipal sludge cake. Water Res 2013; 47:4966-4977. [PMID: 23866136 DOI: 10.1016/j.watres.2013.05.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 05/20/2013] [Accepted: 05/21/2013] [Indexed: 06/02/2023]
Abstract
Fate and removal of 16 steroidal (estrogenic, androgenic and progestogenic) hormones were studied during advanced anaerobic digestion of sludge cake using microwave (MW) pretreatment. Effect of pretreatment temperature (80, 120, 160 °C), operating temperature (mesophilic at 35 ± 2 °C, thermophilic at 55 ± 2 °C) and sludge retention time (SRT: 20, 10, 5 days) were studied employing eight lab-scale semi-continuously fed digesters. To determine the potential effect of MW hydrolysis, hormones were quantified in total (sorbed + soluble) and supernatant (soluble) phases of the digester influent and effluent streams. Seven of 16 hormones were above the method reporting limit (RL) in one or more of the samples. Hormone concentrations in total phase of un-pretreated (control) and pretreated digester feeds ranged in <157-2491 ng/L and <157-749 ng/L, respectively. The three studied factors were found to be statistically significant (95% confidence level) in removal of one or more hormones from soluble and/or total phase. MW hydrolysis of the influent resulted in both release (from sludge matrix) and attenuation of hormones in the soluble phase. Accumulation of estrone (E1) as well as progesterone (Pr) and androstenedione (Ad) in most of the digesters indicated possible microbial transformations among the hormones. Compared to controls, all pretreated digesters had lower total hormone concentrations in their influent streams. At 20 days SRT, highest total removal (E1+E2+Ad +Pr) was observed for the thermophilic control digester (56%), followed by pretreated mesophilic digesters at 120 °C and 160 °C with around 48% efficiency. In terms of conventional performance parameters, relative (to control) improvements of MW pretreated digesters at a 5-d SRT ranged in 98-163% and 57-121%, for volatile solids removal and methane production, respectively.
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Affiliation(s)
- Hanna Hamid
- School of Engineering, University of British Columbia, Okanagan Campus, 1137 Alumni Ave., Kelowna, BC V1V 1V7, Canada
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Bortolotti A, Sánchez-Azqueta A, Maya CM, Velázquez-Campoy A, Hermoso JA, Medina M, Cortez N. The C-terminal extension of bacterial flavodoxin-reductases: involvement in the hydride transfer mechanism from the coenzyme. Biochim Biophys Acta 2013; 1837:33-43. [PMID: 24016470 DOI: 10.1016/j.bbabio.2013.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 08/26/2013] [Accepted: 08/28/2013] [Indexed: 11/28/2022]
Abstract
To study the role of the mobile C-terminal extension present in bacterial class of plant type NADP(H):ferredoxin reductases during catalysis, we generated a series of mutants of the Rhodobacter capsulatus enzyme (RcFPR). Deletion of the six C-terminal amino acids beyond alanine 266 was combined with the replacement A266Y, emulating the structure present in plastidic versions of this flavoenzyme. Analysis of absorbance and fluorescence spectra suggests that deletion does not modify the general geometry of FAD itself, but increases exposure of the flavin to the solvent, prevents a productive geometry of FAD:NADP(H) complex and decreases the protein thermal stability. Although the replacement A266Y partially coats the isoalloxazine from solvent and slightly restores protein stability, this single change does not allow formation of active charge-transfer complexes commonly present in the wild-type FPR, probably due to restraints of C-terminus pliability. A proton exchange process is deduced from ITC measurements during coenzyme binding. All studied RcFPR variants display higher affinity for NADP(+) than wild-type, evidencing the contribution of the C-terminus in tempering a non-productive strong (rigid) interaction with the coenzyme. The decreased catalytic rate parameters confirm that the hydride transfer from NADPH to the flavin ring is considerably hampered in the mutants. Although the involvement of the C-terminal extension from bacterial FPRs in stabilizing overall folding and bent-FAD geometry has been stated, the most relevant contributions to catalysis are modulation of coenzyme entrance and affinity, promotion of the optimal geometry of an active complex and supply of a proton acceptor acting during coenzyme binding.
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Affiliation(s)
- Ana Bortolotti
- Instituto de Biología Molecular y Celular de Rosario, Universidad Nacional de Rosario & CONICET, Rosario, Argentina
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Pan ZZ, Zhu YJ, Chen Z, Ruan CQ, Xu L, Chen QX, Liu B. A protein engineering of Bacillus thuringiensis δ-endotoxin by conjugating with 4"-O-succinoyl abamectin. Int J Biol Macromol 2013; 62:211-6. [PMID: 23999013 DOI: 10.1016/j.ijbiomac.2013.08.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/21/2013] [Accepted: 08/22/2013] [Indexed: 12/23/2022]
Abstract
Conjugation of Bacillus thuringiensis δ-endotoxin (Bt toxin) with other toxins for insect pest control has been proposed as a new efficient strategy with increasing insecticidal toxicity and target range and delay the onset of insect resistance. A modified method was investigated by conjugating Bt toxin with 4"-O-succinoyl abamectin to form a new biocide which was named as BtA. 'Zero-length' cross-linker EDC in combination with NHS activated 4"-O-succinoyl abamectin and extended half-life period of active intermediate for binding to Bt toxin. The dissociation constant for 4"-O-succinoyl abamectin binding to Bt toxin was 6.44 μM by fluorescence quenching analysis. BtA showed a higher insecticidal toxicity against Plutella xylostella, while the relative-toxicity multiple of BtA to Bt toxin was calculated as 5.6. The interaction between Bt toxins with their receptors played a key role in toxicity of Bt toxins. The binding analysis showed the dissociation rate for the binding of BtA to its receptors (7.495 × 10(-3) S(-1)) was twice slower than that of Bt toxin (1.695 × 10(-2) S(-1)). The relative dissociation constant of BtA to Bt toxin was only 29% for the binding to the receptors. These results demonstrated that BtA bound to the receptor in BBMV with significantly higher affinity compared with Bt toxin.
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Affiliation(s)
- Zhi-Zhen Pan
- Agricultural Bio-Resources Institute, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China
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Salcedo G, Cano-Sánchez P, de Gómez-Puyou MT, Velázquez-Campoy A, García-Hernández E. Isolated noncatalytic and catalytic subunits of F1-ATPase exhibit similar, albeit not identical, energetic strategies for recognizing adenosine nucleotides. Biochim Biophys Acta 2014; 1837:44-50. [PMID: 23994287 DOI: 10.1016/j.bbabio.2013.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/21/2013] [Accepted: 08/22/2013] [Indexed: 11/22/2022]
Abstract
The function of F1-ATPase relies critically on the intrinsic ability of its catalytic and noncatalytic subunits to interact with nucleotides. Therefore, the study of isolated subunits represents an opportunity to dissect elementary energetic contributions that drive the enzyme's rotary mechanism. In this study we have calorimetrically characterized the association of adenosine nucleotides to the isolated noncatalytic α-subunit. The resulting recognition behavior was compared with that previously reported for the isolated catalytic β-subunit (N.O. Pulido, G. Salcedo, G. Pérez-Hernández, C. José-Núñez, A. Velázquez-Campoy, E. García-Hernández, Energetic effects of magnesium in the recognition of adenosine nucleotides by the F1-ATPase β subunit, Biochemistry 49 (2010) 5258-5268). The two subunits exhibit nucleotide-binding thermodynamic signatures similar to each other, characterized by enthalpically-driven affinities in the μM range. Nevertheless, contrary to the catalytic subunit that recognizes MgATP and MgADP with comparable strength, the noncatalytic subunit much prefers the triphosphate nucleotide. Besides, the α-subunit depends more on Mg(II) for stabilizing the interaction with ATP, while both subunits are rather metal-independent for ADP recognition. These binding behaviors are discussed in terms of the properties that the two subunits exhibit in the whole enzyme.
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Vierke L, Ahrens L, Shoeib M, Palm WU, Webster EM, Ellis DA, Ebinghaus R, Harner T. In situ air-water and particle-water partitioning of perfluorocarboxylic acids, perfluorosulfonic acids and perfluorooctyl sulfonamide at a wastewater treatment plant. Chemosphere 2013; 92:941-948. [PMID: 23561570 DOI: 10.1016/j.chemosphere.2013.02.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Revised: 02/26/2013] [Accepted: 02/27/2013] [Indexed: 06/02/2023]
Abstract
In situ measurements of air and water phases at a wastewater treatment plant (WWTP) were used to investigate the partitioning behavior of perfluorocarboxylic acids (PFCAs), perfluorosulfonic acids (PFSAs) and perfluorooctyl sulfonamide (HFOSA) and their conjugate bases (PFC(-)s, PFS(-)s, and FOSA(-), respectively). Particle-dissolved (Rd) and air-water (QAW) concentration ratios were determined at different tanks of a WWTP. Sum of concentrations of C4-12,14 PFC(A)s, C4,6,8,10 PFS(A)s and (H)FOSA were as high as 50 pg m(-3) (atmospheric gas phase), 2300 ng L(-1) (aqueous dissolved phase) and 2500 ng L(-1) (aqueous particle phase). Particle-dissolved concentration ratios of total species, log Rd, ranged from -2.9 to 1.3 for PFS(A)s, from -1.9 to 1.1 for PFC(A)s and was 0.71 for (H)FOSA. These field-based values agree well with equilibrium partitioning data reported in the literature, suggesting that any in situ generation from precursors, if they are present in this system, occurs at a slower rate than the rate of approach to equilibrium. Acid QAW were also estimated. Good agreement between the QAW and the air-water equilibrium partition coefficient for C8PFCA suggests that the air above the WWTP tanks is at or near equilibrium with the water. Uncertainties in these QAW values are attributed mainly to variability in pKa values reported in the literature. The WWTP provides a unique environment for investigating environmental fate processes of the PFCAs and PFSAs under 'real' conditions in order to better understand and predict their fate in the environment.
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Affiliation(s)
- Lena Vierke
- Federal Environment Agency (UBA), Section Chemicals, Wörlitzer Platz 1, Dessau-Rosslau, Germany.
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Rüedi-Bettschen D, Wood SL, Gunnell MG, West CM, Pidaparthi RR, Carroll FI, Blough BE, Owens SM. Vaccination protects rats from methamphetamine-induced impairment of behavioral responding for food. Vaccine 2013; 31:4596-602. [PMID: 23906885 DOI: 10.1016/j.vaccine.2013.07.038] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 07/10/2013] [Accepted: 07/16/2013] [Indexed: 01/21/2023]
Abstract
(+)-Methamphetamine (METH) addiction is a chronic disease that interferes with fundamental brain-mediated behaviors and biological functions like eating. These studies present preclinical efficacy and safety profiles for a METH conjugate vaccine (IC(KLH)-SMO9) designed to treat METH abuse. ICKLH-SMO9 efficacy and safety were assessed over a 16-week period by monitoring general health and stability of responding in a food maintained behavioral paradigm. Male Sprague-Dawley rats were trained to lever press for food reinforcers until stable behavior was established. Rats (n=9/group) were then immunized with 100 μg of a control antigenic carrier protein (IC(KLH)-Cys) or IC(KLH)-SMO9 in Alhydrogel adjuvant, with booster immunizations at 4, 8 and 12 weeks. Health, immunization site and behavior were assessed daily. No adverse effects were found. During weeks 14-16, when antibody titers and METH affinity (K(d)=13.9 ± 1.7 nM) were maximal, all rats received progressively higher METH doses (0.3-3.0 mg/kg) every 3-4 days, followed by behavioral testing. Even though the lower METH doses from 0.3 to 1.0 mg/kg produced no impairment in food maintained behavior, 3.0-mg/kg in control rats showed significantly (p<0.05) reduced response rates and number of reinforcers earned, as well as reduced food intake. In sharp contrast, the IC(KLH)-SMO9 group showed no changes in food maintained behavior at any METH dose, even though METH serum concentrations showed profound increases due to anti-METH antibody binding. These findings suggest the IC(KLH)-SMO9 vaccine is effective and safe at reducing adverse METH-induced effects, even at high METH doses.
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Affiliation(s)
- Daniela Rüedi-Bettschen
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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Li H, Cao W, Chen Z, Acheampong DO, Jin H, Li D, Zhang J, Wang M. The antiangiogenic activity of a soluble fragment of the VEGFR extracellular domain. Biomed Pharmacother 2013; 67:599-606. [PMID: 23906761 DOI: 10.1016/j.biopha.2013.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 06/17/2013] [Indexed: 12/30/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) is a key regulator of pathological angiogenesis and vascular permeability and overexpressed by most solid tumors. VEGF receptor-2 (VEGFR-2 or kinase-insert domain-containing receptor as it is called in human, KDR) is a specific receptor of VEGF with a high binding affinity. A solube recombinant extracellular domain 1-3 of human VEGFR-2 (rKDR1-3) was expressed in Escherichia coli (E. Coli) and purified from the bacterial periplasmic extracts by immobilized metal affinity chromatography and anion exchange chromatography to inhibit the VEGF-induced angiogenesis. A surface plasmon resonance (SPR) technology was adopted to analyze the affinity and kinetics constant between rKDR1-3 and VEGF165. Under the given experimental conditions, the association rate constant Ka was 1.06×10(5)M(-1) S(-1), the dissociation rate Kd was 6.09×10(-3) S(-1), the dissociation constant KD was 5.74×10(-8)M. The effect of rKDR1-3 on VEGF-induced endothelial cell proliferation was studied using MTT assay, scratch-wound healing assay and chorioallantoic membrane (CAM) assay. The results showed that rKDR1-3 could inhibit neovascularization and serve as a useful drug candidate in research, diagnostics and therapy of cancer.
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Affiliation(s)
- Haixin Li
- State Key Laboratory of Natural Medicines (China Pharmaceutical University), School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, PR China
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Tiwari M, Mikuni S, Muto H, Kinjo M. Determination of dissociation constant of the NFκB p50/p65 heterodimer using fluorescence cross-correlation spectroscopy in the living cell. Biochem Biophys Res Commun 2013; 436:430-5. [PMID: 23751347 DOI: 10.1016/j.bbrc.2013.05.121] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 05/29/2013] [Indexed: 12/29/2022]
Abstract
Two-laser-beam fluorescence cross-correlation spectroscopy (FCCS) is promising technique that provides quantitative information about the interactions of biomolecules. The p50/p65 heterodimer is the most abundant and well understood of the NFκB dimers in most cells. However, the quantitative value of affinity, namely the K(d), for the heterodimer in living cells is not known yet. To quantify the heterodimerization of the IPT domain of p50/p65 in the living cell, we used two-laser-beam FCCS. The K(d) values of mCherry2- and EGFP-fused p50 and p65 were determined to be 0.46 μM in the cytoplasm and 1.06 μM in the nucleus of the living cell. These results suggest the different binding affinities of the p50/p65 heterodimer in the cytoplasm and nucleus of the living cell and different complex formation in each region.
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Affiliation(s)
- Manisha Tiwari
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan
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Wang CW, Chung WH, Cheng YF, Ying NW, Peck K, Chen YT, Hung SI. A new nucleic acid-based agent inhibits cytotoxic T lymphocyte-mediated immune disorders. J Allergy Clin Immunol 2013; 132:713-722.e11. [PMID: 23791505 DOI: 10.1016/j.jaci.2013.04.036] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 03/16/2013] [Accepted: 04/17/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and graft-versus-host disease (GVHD) are distinct immune reactions elicited by drugs or allogeneic antigens; however, they share a pathomechanism with the activation of cytotoxic T lymphocytes (CTLs). CTLs produce cytotoxic proteins, cytokines, chemokines, or immune alarmins, such as granulysin (GNLY), leading to the extensive tissue damage and systemic inflammation seen in patients with SJS/TEN or GVHD. Currently, there is no effective therapeutic agent specific for CTL-mediated immune disorders. OBJECTIVES By targeting GNLY(+) CTLs, we aimed to develop a nucleic acid-based agent consisting of an anti-CD8 aptamer with GNLY small interfering RNA (siRNA). METHODS We performed systematic evolution of ligands using exponential enrichment to select and identify effective anti-CD8 aptamers. We developed an aptamer-siRNA chimera using a "sticky bridge" method by conjugating the aptamer with siRNA. We analyzed the inhibitory effects of the aptamer-siRNA chimera on CTL responses in patients with SJS/TEN or GVHD. RESULTS We identified a novel DNA aptamer (CD8AP17s) targeting CTLs. This aptamer could be specifically internalized into human CTLs. We generated the CD8AP17s aptamer-GNLY siRNA chimera, which showed a greater than 79% inhibitory effect on the production of GNLY by drug/alloantigen-activated T cells. The CD8AP17s aptamer-GNLY siRNA chimera decreased cytotoxicity in in vitro models of both SJS/TEN (elicited by drug-specific antigen) and GVHD (elicited by allogeneic antigens). CONCLUSIONS Our results identified a new nucleic acid-based agent (CD8 aptamer-GNLY siRNA chimera) that can significantly inhibit CTL-mediated drug hypersensitivity, such as that seen in patients with SJS/TEN, as well as the alloreactivity seen in patients with GVHD. This study provides a novel therapeutic strategy for CTL-mediated immune disorders.
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Affiliation(s)
- Chuang-Wei Wang
- Department and Institute of Pharmacology, School of Medicine, Infection and Immunity Research Center, National Yang-Ming University, Taipei, Taiwan; Molecular Medicine Program, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
| | - Wen-Hung Chung
- Department of Dermatology, Drug Hypersensitivity Clinical and Research Center, Chang Gung Memorial Hospitals, Keelung, Linko, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Yi-Fang Cheng
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Nien-Wen Ying
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Konan Peck
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Yuan-Tsong Chen
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Shuen-Iu Hung
- Department and Institute of Pharmacology, School of Medicine, Infection and Immunity Research Center, National Yang-Ming University, Taipei, Taiwan; Molecular Medicine Program, National Yang-Ming University and Academia Sinica, Taipei, Taiwan.
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Morin N, Morissette M, Grégoire L, Gomez-Mancilla B, Gasparini F, Di Paolo T. Chronic treatment with MPEP, an mGlu5 receptor antagonist, normalizes basal ganglia glutamate neurotransmission in L-DOPA-treated parkinsonian monkeys. Neuropharmacology 2013; 73:216-31. [PMID: 23756168 DOI: 10.1016/j.neuropharm.2013.05.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 05/17/2013] [Accepted: 05/18/2013] [Indexed: 10/26/2022]
Abstract
Metabotropic glutamate 5 (mGlu5) receptor antagonists reduce L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesias (LID) in Parkinson's disease (PD). The aim of this study was to investigate the long-term effect of the prototypal mGlu5 receptor antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) on glutamate receptors known to be involved in the development of LID in the de novo chronic treatment of monkeys lesioned with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). MPTP monkeys were treated for one month with L-DOPA and developed dyskinesias while those treated with L-DOPA and MPEP (10 mg/kg) developed significantly less. Normal control and saline-treated MPTP monkeys were also included. All MPTP monkeys were extensively and similarly denervated. The basal ganglia [(3)H]ABP688 specific binding (mGlu5 receptors) was elevated in L-DOPA-treated MPTP monkeys compared to controls but not in those treated with L-DOPA and MPEP; dyskinesia scores of these monkeys correlated positively with their [(3)H]ABP688 specific binding. Striatal density (B(max)) of [(3)H]ABP688 specific binding increased in L-DOPA-treated MPTP monkeys compared to other groups and affinity (Kd) remained unchanged. Striatal mGlu5 receptor mRNA remained unchanged following treatments. Elevated basal ganglia specific binding of [(3)H]Ro 25-6981 (NMDA NR1/NR2B receptors), [(3)H]Ro 48-8587 (AMPA receptors) but not [(3)H]CGP-39653 (NMDA NR1/NR2A receptors) was observed only in L-DOPA-treated MPTP monkeys; dyskinesias scores correlated with binding. By contrast, basal ganglia [(3)H]LY341495 specific binding (mGlu2/3 receptors) decreased in L-DOPA-treated MPTP monkeys compared to controls, saline and L-DOPA + MPEP treated MPTP monkeys; dyskinesias scores correlated negatively with this binding. Hence, chronic MPEP treatment reduces the development of LID and is associated with a normalization of glutamate neurotransmission.
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Affiliation(s)
- Nicolas Morin
- Neuroscience Research Unit, Laval University Medical Center (CHUQ), Quebec, QC, Canada
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Lummis SCR, Thompson AJ. Agonists and antagonists induce different palonosetron dissociation rates in 5-HT₃A and 5-HT₃AB receptors. Neuropharmacology 2013; 73:241-6. [PMID: 23747573 PMCID: PMC3778450 DOI: 10.1016/j.neuropharm.2013.05.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 04/19/2013] [Accepted: 05/08/2013] [Indexed: 11/30/2022]
Abstract
Palonosetron is a potent 5-HT3 receptor antagonist with a unique structure and some unusual properties. Here we explore the properties of palonosetron at heterologously expressed 5-HT3A and 5-HT3AB receptors. We used receptors expressed in HEK293 cells, and functionally analysed them using a membrane potential sensitive dye in a Flexstation, which revealed IC50s of 0.24 nM and 0.18 nM for 5-HT3A and 5-HT3AB receptors respectively. Radioligand binding studies with [3H]palonosetron revealed similar Kds: 0.34 nM for 5-HT3A and 0.15 nM for 5-HT3AB receptors. Kinetic studies showed palonosetron association and dissociation rates were slightly faster in 5-HT3AB than 5-HT3A receptors, and for both subtypes dissociation rates were ligand-dependent, with antagonists causing more rapid dissociation than agonists. Similar ligand effects were not observed for [3H]granisetron dissociation studies. These data support previous studies which show palonosetron has actions distinct to other 5-HT3 receptor antagonists, and the slow rates observed for agonist induced dissociation (t1/2 > 10 h) could at least partly explain the long duration of palonosetron effects in vivo. Palonosetron IC50s and Kds for 5-HT3A and 5-HT3AB receptors in HEK293 cells are similar. Palonosetron association and dissociation rates are slower at 5-HT3A than 5-HT3AB receptors. Agonist-induced palonosetron dissociation rates are slower than those for antagonists in both 5-HT3A and 5-HT3AB receptors. Agonist- and antagonist-induced granisetron dissociation rates are similar in both 5-HT3A and 5-HT3AB receptors. Palonosetron and granisetron have distinct actions.
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Affiliation(s)
- Sarah C R Lummis
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.
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Jesse HE, Nye TL, McLean S, Green J, Mann BE, Poole RK. Cytochrome bd-I in Escherichia coli is less sensitive than cytochromes bd-II or bo'' to inhibition by the carbon monoxide-releasing molecule, CORM-3: N-acetylcysteine reduces CO-RM uptake and inhibition of respiration. Biochim Biophys Acta 2013; 1834:1693-703. [PMID: 23624261 PMCID: PMC3787766 DOI: 10.1016/j.bbapap.2013.04.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 04/18/2013] [Accepted: 04/19/2013] [Indexed: 11/04/2022]
Abstract
Background: CO-releasing molecules (CO-RMs) are potential therapeutic agents, able to deliver CO – a critical gasotransmitter – in biological environments. CO-RMs are also effective antimicrobial agents; although the mechanisms of action are poorly defined, haem-containing terminal oxidases are primary targets. Nevertheless, it is clear from several studies that the effects of CO-RMs on biological systems are frequently not adequately explained by the release of CO: CO-RMs are generally more potent inhibitors than is CO gas and other effects of the molecules are evident. Methods: Because sensitivity to CO-RMs cannot be predicted by sensitivity to CO gas, we assess the differential susceptibilities of strains, each expressing only one of the three terminal oxidases of E. coli — cytochrome bd-I, cytochrome bd-II and cytochrome bo′, to inhibition by CORM-3. We present the first sensitive measurement of the oxygen affinity of cytochrome bd-II (Km 0.24 μM) employing globin deoxygenation. Finally, we investigate the way(s) in which thiol compounds abolish the inhibitory effects of CORM-2 and CORM-3 on respiration, growth and viability, a phenomenon that is well documented, but poorly understood. Results: We show that a strain expressing cytochrome bd-I as the sole oxidase is least susceptible to inhibition by CORM-3 in its growth and respiration of both intact cells and membranes. Growth studies show that cytochrome bd-II has similar CORM-3 sensitivity to cytochrome bo′. Cytochromes bo′ and bd-II also have considerably lower affinities for oxygen than bd-I. We show that the ability of N-acetylcysteine to abrogate the toxic effects of CO-RMs is not attributable to its antioxidant effects, or prevention of CO targeting to the oxidases, but may be largely due to the inhibition of CO-RM uptake by bacterial cells. Conclusions: A strain expressing cytochrome bd-I as the sole terminal oxidase is least susceptible to inhibition by CORM-3. N-acetylcysteine is a potent inhibitor of CO-RM uptake by E. coli. General significance: Rational design and exploitation of CO-RMs require a fundamental understanding of their activity. CO and CO-RMs have multifaceted effects on mammalian and microbial cells; here we show that the quinol oxidases of E. coli are differentially sensitive to CORM-3. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins. Cytochrome bd-I is a CORM- insensitive heme-protein in E. coli. The oxygen affinity of the ‘third oxidase’, cytochrome bd-II is low (Km 0.24 μM). Non-thiol antioxidants do not prevent CO-RM-mediated inhibition of respiration. N-acetylcysteine reduces the uptake of CORM-2 and CORM-3 by E. coli.
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Affiliation(s)
- Helen E Jesse
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, S10 2TN, UK.
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Spyrakis F, Lucas F, Bidon-Chanal A, Viappiani C, Guallar V, Luque FJ. Comparative analysis of inner cavities and ligand migration in non-symbiotic AHb1 and AHb2. Biochim Biophys Acta 2013; 1834:1957-67. [PMID: 23583621 DOI: 10.1016/j.bbapap.2013.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 03/30/2013] [Accepted: 04/03/2013] [Indexed: 10/27/2022]
Abstract
This study reports a comparative analysis of the topological properties of inner cavities and the intrinsic dynamics of non-symbiotic hemoglobins AHb1 and AHb2 from Arabidopsis thaliana. The two proteins belong to the 3/3 globin fold and have a sequence identity of about 60%. However, it is widely assumed that they have distinct physiological roles. In order to investigate the structure-function relationships in these proteins, we have examined the bis-histidyl and ligand-bound hexacoordinated states by atomistic simulations using in silico structural models. The results allow us to identify two main pathways to the distal cavity in the bis-histidyl hexacoordinated proteins. Nevertheless, a larger accessibility to small gaseous molecules is found in AHb2. This effect can be attributed to three factors: the mutation Leu35(AHb1)→Phe32(AHb2), the enhanced flexibility of helix B, and the more favorable energetic profile for ligand migration to the distal cavity. The net effect of these factors would be to facilitate the access of ligands, thus compensating the preference for the fully hexacoordination of AHb2, in contrast to the equilibrium between hexa- and pentacoordinated species in AHb1. On the other hand, binding of the exogenous ligand introduces distinct structural changes in the two proteins. A well-defined tunnel is formed in AHb1, which might be relevant to accomplish the proposed NO detoxification reaction. In contrast, no similar tunnel is found in AHb2, which can be ascribed to the reduced flexibility of helix E imposed by the larger number of salt bridges compared to AHb1. This feature would thus support the storage and transport functions proposed for AHb2. This article is part of a Special Issue entitled: Oxygen Binding and Sensing Proteins.
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Affiliation(s)
- Francesca Spyrakis
- Dipartimento di Scienze degli Alimenti, Università degli Studi di Parma, Parma, Italy.
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