1
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Mendola RJ, Biswas L, Schindler K, Walmsley RH, Russell H, Angle M, Garrisi GJ. Influx of zwitterionic buffer after intracytoplasmic sperm injection (ICSI) membrane piercing alters the transcriptome of human oocytes. J Assist Reprod Genet 2024; 41:1341-1356. [PMID: 38436798 PMCID: PMC11143126 DOI: 10.1007/s10815-024-03064-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2024] [Indexed: 03/05/2024] Open
Abstract
PURPOSE/STUDY QUESTION Does piercing oocyte membranes during ICSI allow the influx of surrounding zwitterionic buffer into human oocytes and result in altered developmental competence? METHODS Human oocytes directed to IRB-approved research were used to determine the unrestricted influx of surrounding buffer into the oocyte after piercing of membranes via confocal fluorescence microscopy (n = 80 human MII oocytes) and the influence of the select buffer influx of HEPES, MOPS, and bicarbonate buffer on the oocyte transcriptome using ultra-low input RNA sequencing (n = 40 human MII oocytes). RESULTS Piercing membranes of human MII oocytes during sham-ICSI resulted in the unrestricted influx of surrounding culture buffer into the oocyte that was beyond technician control. Transcriptome analysis revealed statistically significant decreased cytoskeletal transcripts in the pierced buffer cohorts, higher levels of embryo competency transcripts (IGF2 and G6PD) in the bicarbonate buffer cohort, higher levels of stress-induced transcriptional repressor transcripts (MAF1) in the HEPES and MOPS cohorts, and decreased levels of numerous chromosomal maintenance transcripts (SMC3) in the HEPES buffer cohort. The HEPES buffer cohort also revealed higher levels of transcripts suggesting increased oxidative (GPX1) and lysosomal stress (LAMP1). CONCLUSION The influence of zwitterionic buffer on intrinsic cellular mechanisms provides numerous concerns for their use in IVF clinical applications. The primary concern is the ICSI procedure, in which the surrounding buffer is allowed influx into the oocytes after membrane piercing. Selecting a physiological bicarbonate buffer may reduce imposed stress on oocytes, resulting in improved embryo development and clinical results because intracellular MOPS, and especially HEPES, may negatively impact intrinsic biological mechanisms, as revealed by transcriptome changes. These findings further support the utilization of bicarbonate buffer as the oocyte-holding medium during ICSI.
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Affiliation(s)
- Robert J Mendola
- Institute for Reproductive Medicine and Science (IRMS) at Saint Barnabas, Livingston, NJ, USA.
| | - Leelabati Biswas
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
- Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - Karen Schindler
- Department of Genetics, Rutgers University, Piscataway, NJ, USA
| | - Renee H Walmsley
- Institute for Reproductive Medicine and Science (IRMS) at Saint Barnabas, Livingston, NJ, USA
| | - Helena Russell
- Eastern Virginia Medical School (EVMS), Norfolk, VA, USA
| | - Marlane Angle
- Eastern Virginia Medical School (EVMS), Norfolk, VA, USA
| | - G John Garrisi
- Institute for Reproductive Medicine and Science (IRMS) at Saint Barnabas, Livingston, NJ, USA
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2
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Cvjetan N, Schuler LD, Ishikawa T, Walde P. Optimization and Enhancement of the Peroxidase-like Activity of Hemin in Aqueous Solutions of Sodium Dodecylsulfate. ACS OMEGA 2023; 8:42878-42899. [PMID: 38024761 PMCID: PMC10652838 DOI: 10.1021/acsomega.3c05915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/10/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023]
Abstract
Iron porphyrins play several important roles in present-day living systems and probably already existed in very early life forms. Hemin (= ferric protoporphyrin IX = ferric heme b), for example, is the prosthetic group at the active site of heme peroxidases, catalyzing the oxidation of a number of different types of reducing substrates after hemin is first oxidized by hydrogen peroxide as the oxidizing substrate of the enzyme. The active site of heme peroxidases consists of a hydrophobic pocket in which hemin is embedded noncovalently and kept in place through coordination of the iron atom to a proximal histidine side chain of the protein. It is this partially hydrophobic local environment of the enzyme which determines the efficiency with which the sequential reactions of the oxidizing and reducing substrates proceed at the active site. Free hemin, which has been separated from the protein moiety of heme peroxidases, is known to aggregate in an aqueous solution and exhibits low catalytic activity. Based on previous reports on the use of surfactant micelles to solubilize free hemin in a nonaggregated state, the peroxidase-like activity of hemin in the presence of sodium dodecyl sulfate (SDS) at concentrations below and above the critical concentration for SDS micelle formation (critical micellization concentration (cmc)) was systematically investigated. In most experiments, 3,3',5,5'-tetramethylbenzidine (TMB) was applied as a reducing substrate at pH = 7.2. The presence of SDS clearly had a positive effect on the reaction in terms of initial reaction rate and reaction yield, even at concentrations below the cmc. The highest activity correlated with the cmc value, as demonstrated for reactions at three different HEPES concentrations. The 4-(2-hydroxyethyl)-1-piperazineethanesulfonate salt (HEPES) served as a pH buffer substance and also had an accelerating effect on the reaction. At the cmc, the addition of l-histidine (l-His) resulted in a further concentration-dependent increase in the peroxidase-like activity of hemin until a maximal effect was reached at an optimal l-His concentration, probably corresponding to an ideal mono-l-His ligation to hemin. Some of the results obtained can be understood on the basis of molecular dynamics simulations, which indicated the existence of intermolecular interactions between hemin and HEPES and between hemin and SDS. Preliminary experiments with SDS/dodecanol vesicles at pH = 7.2 showed that in the presence of the vesicles, hemin exhibited similar peroxidase-like activity as in the case of SDS micelles. This supports the hypothesis that micelle- or vesicle-associated ferric or ferrous iron porphyrins may have played a role as primitive catalysts in membranous prebiotic compartment systems before cellular life emerged.
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Affiliation(s)
- Nemanja Cvjetan
- Department
of Materials, ETH-Zürich, Leopold-Ruzicka-Weg 4, 8093 Zürich, Switzerland
| | | | - Takashi Ishikawa
- Department
of Biology and Chemistry, Paul Scherrer Institute and Department of
Biology, ETH-Zürich, Forschungsstrasse 111, 5232 Villigen PSI, Switzerland
| | - Peter Walde
- Department
of Materials, ETH-Zürich, Leopold-Ruzicka-Weg 4, 8093 Zürich, Switzerland
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3
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Savva A, Hama A, Herrera‐López G, Schmidt T, Migliaccio L, Steiner N, Kawan M, Fiumelli H, Magistretti PJ, McCulloch I, Baran D, Gasparini N, Schindl R, Głowacki ED, Inal S. Photo-Chemical Stimulation of Neurons with Organic Semiconductors. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2300473. [PMID: 37661572 PMCID: PMC10625067 DOI: 10.1002/advs.202300473] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 07/17/2023] [Indexed: 09/05/2023]
Abstract
Recent advances in light-responsive materials enabled the development of devices that can wirelessly activate tissue with light. Here it is shown that solution-processed organic heterojunctions can stimulate the activity of primary neurons at low intensities of light via photochemical reactions. The p-type semiconducting polymer PDCBT and the n-type semiconducting small molecule ITIC (a non-fullerene acceptor) are coated on glass supports, forming a p-n junction with high photosensitivity. Patch clamp measurements show that low-intensity white light is converted into a cue that triggers action potentials in primary cortical neurons. The study shows that neat organic semiconducting p-n bilayers can exchange photogenerated charges with oxygen and other chemical compounds in cell culture conditions. Through several controlled experimental conditions, photo-capacitive, photo-thermal, and direct hydrogen peroxide effects on neural function are excluded, with photochemical delivery being the possible mechanism. The profound advantages of low-intensity photo-chemical intervention with neuron electrophysiology pave the way for developing wireless light-based therapy based on emerging organic semiconductors.
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Affiliation(s)
- Achilleas Savva
- Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
- Department of Chemical Engineering and BiotechnologyUniversity of CambridgeCambridgeCB30ASUK
| | - Adel Hama
- Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Gabriel Herrera‐López
- Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Tony Schmidt
- Gottfried Schatz Research CenterChair of BiophysicsMedical University of GrazNeue Stiftingtalstraße 6Graz8010Austria
| | - Ludovico Migliaccio
- Bioelectronics Materials and Devices LaboratoryCentral European Institute of TechnologyBrno University of TechnologyPurkyňova 123Brno61200Czech Republic
| | - Nadia Steiner
- Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Malak Kawan
- Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Hubert Fiumelli
- Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Pierre J. Magistretti
- Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Iain McCulloch
- Physical Science and Engineering (PSE)KAUST Solar Center (KSC)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Derya Baran
- Physical Science and Engineering (PSE)KAUST Solar Center (KSC)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Nicola Gasparini
- Department of Chemistry and Centre for Processable ElectronicsImperial College LondonLondonW12 0BZUK
| | - Rainer Schindl
- Gottfried Schatz Research CenterChair of BiophysicsMedical University of GrazNeue Stiftingtalstraße 6Graz8010Austria
| | - Eric D. Głowacki
- Bioelectronics Materials and Devices LaboratoryCentral European Institute of TechnologyBrno University of TechnologyPurkyňova 123Brno61200Czech Republic
| | - Sahika Inal
- Biological and Environmental Science and EngineeringKing Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
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4
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Accolla RP, Liang JP, Lansberry TR, Miravet IL, Loaisiga M, Sardi BL, Stabler CL. Engineering Modular, Oxygen-Generating Microbeads for the In Situ Mitigation of Cellular Hypoxia. Adv Healthc Mater 2023; 12:e2300239. [PMID: 36971050 PMCID: PMC10522802 DOI: 10.1002/adhm.202300239] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Indexed: 03/29/2023]
Abstract
Insufficient oxygenation is a key obstacle in the design of clinically scalable tissue-engineered grafts. In this work, an oxygen-generating composite material, termed OxySite, is created through the encapsulation of calcium peroxide (CaO2 ) within polydimethylsiloxane and formulated into microbeads for ease in tissue integration. Key material parameters of reactant loading, porogen addition, microbead size, and an outer rate-limiting layer are modulated to characterize oxygen generation kinetics and their suitability for cellular applications. In silico models are developed to predict the local impact of different OxySite microbead formulations on oxygen availability within an idealized cellular implant. Promising OxySite microbead variants are subsequently coencapsulated with murine β-cells within macroencapsulation devices, resulting in improved cellular metabolic activity and function under hypoxic conditions when compared to controls. Additionally, the coinjection of optimized OxySite microbeads with murine pancreatic islets within a confined transplant site demonstrates ease of integration and improved primary cell function. These works highlight the broad translatability delivered by this new oxygen-generating biomaterial format, whereby the modularity of the material provides customization of the oxygen source to the specific needs of the cellular implant.
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Affiliation(s)
- Robert P. Accolla
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Jia-Pu Liang
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Taylor R. Lansberry
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Irayme Labrada Miravet
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Marlon Loaisiga
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Baltasar Lopez Sardi
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Cherie L. Stabler
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
- Department of Immunology and Pathology, College of Medicine, University of Florida, Gainesville, FL, USA
- University of Florida Diabetes Institute, Gainesville, FL, USA
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5
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Hausladen DM, Peña J. Organic buffers act as reductants of abiotic and biogenic manganese oxides. Sci Rep 2023; 13:6498. [PMID: 37081009 PMCID: PMC10119380 DOI: 10.1038/s41598-023-32691-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 03/31/2023] [Indexed: 04/22/2023] Open
Abstract
Proton activity is the master variable in many biogeochemical reactions. To control pH, laboratory studies involving redox-sensitive minerals like manganese (Mn) oxides frequently use organic buffers (typically Good's buffers); however, two Good's buffers, HEPES and MES, have been shown to reduce Mn(IV) to Mn(III). Because Mn(III) strongly controls mineral reactivity, avoiding experimental artefacts that increase Mn(III) content is critical to avoid confounding results. Here, we quantified the extent of Mn reduction upon reaction between Mn oxides and several Good's buffers (MES, pKa = 6.10; PIPES, pKa = 6.76; MOPS, pKa = 7.28; HEPES, pKa = 7.48) and TRIS (pKa = 8.1) buffer. For δ-MnO2, Mn reduction was rapid, with up to 35% solid-phase Mn(III) generated within 1 h of reaction with Good's buffers; aqueous Mn was minimal in all Good's buffers experiments except those where pH was one unit below the buffer pKa and the reaction proceeded for 24 h. Additionally, the extent of Mn reduction after 24 h increased in the order MES < MOPS < PIPES < HEPES << TRIS. Of the variables tested, the initial Mn(II,III) content had the greatest effect on susceptibility to reduction, such that Mn reduction scaled inversely with the initial average oxidation number (AMON) of the oxide. For biogenic Mn oxides, which consist of a mixture of Mn oxides, bacterial cells and extracelluar polymeric substances, the extent of Mn reduction was lower than predicted from experiments using abiotic analogs and may result from biotic re-oxidation of reduced Mn or a difference in the reducibility of abiotic versus biogenic oxides. The results from this study show that organic buffers, including morpholinic and piperazinic Good's buffers and TRIS, should be avoided for pH control in Mn oxide systems due to their ability to transfer electrons to Mn, which modifies the composition and reactivity of these redox-active minerals.
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Affiliation(s)
- Debra M Hausladen
- Institute of Earth Surface Dynamics, University of Lausanne, 1015, Lausanne, Switzerland
- Department of Civil and Building Engineering, Université de Sherbrooke, Sherbrooke, QC, J1K 2R1, Canada
| | - Jasquelin Peña
- Institute of Earth Surface Dynamics, University of Lausanne, 1015, Lausanne, Switzerland.
- Department of Civil and Environmental Engineering, University of California, Davis, CA, 95616, USA.
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6
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Walter M, Schenkeveld WD, Tomatis M, Schelch K, Peter-Vörösmarty B, Geroldinger G, Gille L, Bruzzoniti MC, Turci F, Kraemer SM, Grusch M. The Potential Contribution of Hexavalent Chromium to the Carcinogenicity of Chrysotile Asbestos. Chem Res Toxicol 2022; 35:2335-2347. [PMID: 36410050 PMCID: PMC9768810 DOI: 10.1021/acs.chemrestox.2c00314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chrysotile asbestos is a carcinogenic mineral that has abundantly been used in industrial and consumer applications. The carcinogenicity of the fibers is partly governed by reactive Fe surface sites that catalyze the generation of highly toxic hydroxyl radicals (HO•) from extracellular hydrogen peroxide (H2O2). Chrysotile also contains Cr, typically in the low mass permille range. In this study, we examined the leaching of Cr from fibers at the physiological lung pH of 7.4 in the presence and absence of H2O2. Furthermore, we investigated the potential of cells from typical asbestos-burdened tissues and cancers to take up Cr leached from chrysotile in PCR expression, immunoblot, and cellular Cr uptake experiments. Finally, the contribution of Cr to fiber-mediated H2O2 decomposition and HO• generation was studied. Chromium readily dissolved from chrysotile fibers in its genotoxic and carcinogenic hexavalent redox state upon oxidation by H2O2. Lung epithelial, mesothelial, lung carcinoma, and mesothelioma cells expressed membrane-bound Cr(VI) transporters and accumulated Cr up to 10-fold relative to the Cr(VI) concentration in the spiked medium. Conversely, anion transporter inhibitors decreased cellular Cr(VI) uptake up to 45-fold. Finally, chromium associated with chrysotile neither decomposed H2O2 nor contributed to fiber-mediated HO• generation. Altogether, our results support the hypothesis that Cr may leach from inhaled chrysotile in its hexavalent state and subsequently accumulate in cells of typically asbestos-burdened tissues, which could contribute to the carcinogenicity of chrysotile fibers. However, unlike Fe, Cr did not significantly contribute to the adverse radical production of chrysotile.
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Affiliation(s)
- Martin Walter
- Department
of Environmental Geosciences, University
of Vienna, Althanstraße
14 (UZA II), 1090Vienna, Austria
| | - Walter D.C. Schenkeveld
- Department
of Environmental Geosciences, University
of Vienna, Althanstraße
14 (UZA II), 1090Vienna, Austria,
| | - Maura Tomatis
- Department
of Veterinary Sciences, University of Torino, L.go Paolo Braccini, 2, Grugliasco, 10095 (TO), Italy,“G.Scansetti”
Interdepartmental Center for Studies of Asbestos and Other Toxic Particulates, Via Pietro Giuria, 7, 10125Torino, Italy
| | - Karin Schelch
- Center
for Cancer Research, Medical University
of Vienna, Borschkegasse 8a, 1090Vienna, Austria
| | | | - Gerald Geroldinger
- Institute
of Pharmacology and Toxicology, University of Veterinary Medicine, Vienna, Veterinärplatz 1, 1210Vienna, Austria
| | - Lars Gille
- Institute
of Pharmacology and Toxicology, University of Veterinary Medicine, Vienna, Veterinärplatz 1, 1210Vienna, Austria
| | - Maria C. Bruzzoniti
- Department
of Chemistry, University of Torino, Via Pietro Giuria, 7, 10125Torino, Italy
| | - Francesco Turci
- “G.Scansetti”
Interdepartmental Center for Studies of Asbestos and Other Toxic Particulates, Via Pietro Giuria, 7, 10125Torino, Italy,Department
of Chemistry, University of Torino, Via Pietro Giuria, 7, 10125Torino, Italy
| | - Stephan M. Kraemer
- Department
of Environmental Geosciences, University
of Vienna, Althanstraße
14 (UZA II), 1090Vienna, Austria
| | - Michael Grusch
- Center
for Cancer Research, Medical University
of Vienna, Borschkegasse 8a, 1090Vienna, Austria
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7
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Rastinfard A, Dalisson B, Barralet J. Aqueous decomposition behavior of solid peroxides: Effect of pH and buffer composition on oxygen and hydrogen peroxide formation. Acta Biomater 2022; 145:390-402. [PMID: 35405328 DOI: 10.1016/j.actbio.2022.04.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 03/29/2022] [Accepted: 04/01/2022] [Indexed: 12/11/2022]
Abstract
The ability of solid peroxides to provide sustained release of both oxygen and hydrogen peroxide makes them potentially suitable for oxygen release or antibacterial applications. Most recent reports using solid peroxides to augment oxygen levels do so by compounding solid peroxide powders in polymers to retard the aqueous decomposition. Compounds with peroxidase activity may be added to reduce hydrogen peroxide toxicity. Peroxides are rarely pure and are mixed with oxide and themselves decompose to form hydroxides in water. Therefore, even if buffering strategies are used, locally the pH at the surface of aqueously immersed peroxide particles is inevitably alkaline. Since pH affects the decomposition of peroxides and hydrogen peroxide stability, this study compared for the first-time the aqueous decomposition products of hydrogen and inorganic peroxides that are in use or have been used for medical applications of have been evaluated preclinically; calcium peroxide (CaO2), magnesium peroxide (MgO2), zinc peroxide (ZnO2), sodium percarbonate (Na2CO3.1.5H2O2) and hydrogen peroxide (H2O2). Since plasma can be approximated to be carbonate buffered phosphate solution, we maintained pH using carbonate and phosphate buffers and compared results with citrate buffers. For a given peroxide compound, we identified not only a strong effect of pH but also of buffer composition on the extent to which oxygen and hydrogen peroxide formation occurred. The influence of buffer composition was not previously appreciated, thereby establishing in vitro parameters for better design of intentional release of specific decomposition species. STATEMENT OF SIGNIFICANCE: This paper compares for the first time the aqueous decomposition products oxygen and hydrogen peroxide of solid peroxy compounds of metal cations, (calcium, magnesium, sodium and zinc) across a pH range that could feasibly be found in the body, (pH 5,7, 9) either physiologically or pathologically. We find that in addition to pH, buffer composition is also a critically important factor, making translation from in vitro models challenging. Cytotoxicity was related to hydrogen peroxide release, alkalinity and in the case of zinc peroxide to the cation itself. In vitro and preclinical studies generally report release data from polymer-peroxide composites and rarely compare peroxides with one another. Together our data provide guidance for oxygen and ROS delivery from these inorganic materials.
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8
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Effects of Hydrogen Peroxide Produced by Catechins on the Aroma of Tea Beverages. Foods 2022; 11:foods11091273. [PMID: 35563996 PMCID: PMC9102859 DOI: 10.3390/foods11091273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/20/2022] [Accepted: 04/26/2022] [Indexed: 02/01/2023] Open
Abstract
Hydrogen peroxide has a significant effect on the flavor of tea beverages. In this study, the yield of hydrogen peroxide in (-)-epigallocatechin gallate (EGCG) solution was first investigated and found to be significantly enhanced under specific conditions, and the above phenomenon was amplified by the addition of linalool. Then, an aqueous hydrogen peroxide solution was added to a linalool solution and it was found that the concentration of linalool was significantly reduced in the above-reconstituted system. These findings were verified by extending the study system to the whole green tea infusions. The results suggested that the production of hydrogen peroxide in tea beverages may be dominated by catechins, with multiple factors acting synergistically, thereby leading to aroma deterioration and affecting the quality of tea beverages. The above results provided a feasible explanation for the deterioration of flavor quality of green tea beverages with shelf life.
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9
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Reiniers MJ, de Haan LR, Reeskamp LF, Broekgaarden M, Hoekstra R, van Golen RF, Heger M. Optimal Use of 2',7'-Dichlorofluorescein Diacetate in Cultured Hepatocytes. Methods Mol Biol 2022; 2451:721-747. [PMID: 35505044 DOI: 10.1007/978-1-0716-2099-1_39] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Oxidative stress is a state that arises when the production of reactive transients overwhelms the cell's capacity to neutralize the oxidants and radicals. This state often coincides with the pathogenesis and perpetuation of numerous chronic diseases. On the other hand, medical interventions such as radiation therapy and photodynamic therapy generate radicals to selectively damage and kill diseased tissue. As a result, the qualification and quantification of oxidative stress are of great interest to those studying disease mechanisms as well as therapeutic interventions. 2',7'-Dichlorodihydrofluorescein-diacetate (DCFH2-DA) is one of the most widely used fluorogenic probes for the detection of reactive transients. The nonfluorescent DCFH2-DA crosses the plasma membrane and is deacetylated by cytosolic esterases to 2',7'-dichlorodihydrofluorescein (DCFH2). The nonfluorescent DCFH2 is subsequently oxidized by reactive transients to form the fluorescent 2',7'-dichlorofluorescein (DCF). The use of DCFH2-DA in hepatocyte-derived cell lines is more challenging because of membrane transport proteins that interfere with probe uptake and retention, among several other reasons. Cancer cells share some of the physiological and biochemical features with hepatocytes, so probe-related technical issues are applicable to cultured malignant cells as well. This study therefore analyzed the in vitro properties of DCFH2-DA in cultured human hepatocytes (HepG2 cells and differentiated and undifferentiated HepaRG cells) to identify methodological and technical features that could impair proper data analysis and interpretation. The main issues that were found and should therefore be accounted for in experimental design include the following: (1) both DCFH2-DA and DCF are taken up rapidly, (2) DCF is poorly retained in the cytosol and exits the cell, (3) the rate of DCFH2 oxidation is cell type-specific, (4) DCF fluorescence intensity is pH-dependent at pH < 7, and (5) the stability of DCFH2-DA in cell culture medium relies on medium composition. Based on the findings, the conditions for the use of DCFH2-DA in hepatocyte cell lines were optimized. Finally, the optimized protocol was reduced to practice and DCFH2-DA was applied to visualize and quantify oxidative stress in real time in HepG2 cells subjected to anoxia/reoxygenation as a source of reactive transients.
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Affiliation(s)
- Megan J Reiniers
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, Department of Pharmaceutics, College of Medicine, Jiaxing University, Jiaxing, Zhejiang, P. R. China
- Department of Surgery, Haaglanden Medisch Centrum, The Hague, The Netherlands
| | - Lianne R de Haan
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, Department of Pharmaceutics, College of Medicine, Jiaxing University, Jiaxing, Zhejiang, P. R. China
- Laboratory Experimental Oncology, Department of Pathology, Erasmus MC, Rotterdam, The Netherlands
| | - Laurens F Reeskamp
- Department of Vascular Medicine, Amsterdam UMC, Location AMC, Amsterdam, The Netherlands
| | - Mans Broekgaarden
- Team Cancer Targets and Experimental Therapeutics, Department Microenvironment Cell Plasticity and Signaling, Institute for Advanced Biosciences, Université de Grenoble-Alpes, Allée des Alpes, La Tronche, France
- INSERM U 1209, CNRS UMR 5309, Allée des Alpes, La Tronche, France
| | - Ruurdtje Hoekstra
- Tytgat Institute for Liver and Intestinal Research, Amsterdam UMC, Location AMC, Amsterdam, The Netherlands
| | - Rowan F van Golen
- Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Michal Heger
- Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, Department of Pharmaceutics, College of Medicine, Jiaxing University, Jiaxing, Zhejiang, P. R. China.
- Laboratory Experimental Oncology, Department of Pathology, Erasmus MC, Rotterdam, The Netherlands.
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
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10
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Ruzza P, Honisch C, Hussain R, Siligardi G. Free Radical Generation in Far-UV Synchrotron Radiation Circular Dichroism Assays-Protein and Buffer Composition Contribution. Int J Mol Sci 2021; 22:11325. [PMID: 34768758 PMCID: PMC8583428 DOI: 10.3390/ijms222111325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 11/29/2022] Open
Abstract
A useful tool to analyze the ligands and/or environmental contribution to protein stability is represented by the Synchrotron Radiation Circular Dichroism UV-denaturation assay that consists in the acquisition of several consecutive repeated far-UV SRCD spectra. Recently we demonstrated that the prevailing mechanism of this denaturation involves the generation of free radicals and reactive oxygen species (ROS). In this work, we analyzed the effect of buffering agents commonly used in spectroscopic measurements, including MOPS (3-(N-morpholino) propanesulfonic acid), HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid), TRIS-HCl (tris-hydroxymethil aminomethane hydrochloride), and phosphate, on the efficiency of protein denaturation caused by exposure to UV radiation. Fluorescence experiments confirmed the presence of ROS and were used to determine the rate of ROS generation. Our results indicate that the efficiency of the denaturation process is strongly influenced by the buffer composition with MOPS and HEPES acting also as scavengers and that the presence of proteins itself influenced the ROS formation rate.
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Affiliation(s)
- Paolo Ruzza
- Institute of Biomolecular Chemistry of CNR, Padua Unit, via Marzolo, 1, 35131 Padova, Italy;
| | - Claudia Honisch
- Institute of Biomolecular Chemistry of CNR, Padua Unit, via Marzolo, 1, 35131 Padova, Italy;
- Department of Chemical Sciences, University of Padua, via Marzolo, 1, 35131 Padova, Italy
| | - Rohanah Hussain
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK;
| | - Giuliano Siligardi
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, UK;
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11
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Zimmermann T, Gebhardt LA, Kreiss L, Schneider C, Arndt S, Karrer S, Friedrich O, Fischer MJM, Bosserhoff AK. Acidified Nitrite Contributes to the Antitumor Effect of Cold Atmospheric Plasma on Melanoma Cells. Int J Mol Sci 2021; 22:ijms22073757. [PMID: 33916572 PMCID: PMC8038463 DOI: 10.3390/ijms22073757] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 03/30/2021] [Accepted: 04/02/2021] [Indexed: 02/06/2023] Open
Abstract
Cold atmospheric plasma (CAP) is partially ionized gas near room temperature with previously reported antitumor effects. Despite extensive research and growing interest in this technology, active components and molecular mechanisms of CAP are not fully understood to date. We used Raman spectroscopy and colorimetric assays to determine elevated nitrite and nitrate levels after treatment with a MiniFlatPlaster CAP device. Previously, we demonstrated CAP-induced acidification. Cellular effects of nitrite and strong extracellular acidification were assessed using live-cell imaging of intracellular Ca2+ levels, cell viability analysis as well as quantification of p21 and DNA damage. We further characterized these observations by analyzing established molecular effects of CAP treatment. A synergistic effect of nitrite and acidification was found, leading to strong cytotoxicity in melanoma cells. Interestingly, protein nitration and membrane damage were absent after treatment with acidified nitrite, thereby challenging their contribution to CAP-induced cytotoxicity. Further, phosphorylation of ERK1/2 was increased after treatment with both acidified nitrite and indirect CAP. This study characterizes the impact of acidified nitrite on melanoma cells and supports the importance of RNS during CAP treatment. Further, it defines and evaluates important molecular mechanisms that are involved in the cancer cell response to CAP.
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Affiliation(s)
- Tom Zimmermann
- Emil-Fischer-Center, Institute of Biochemistry, University of Erlangen-Nuernberg, 91054 Erlangen, Germany; (T.Z.); (C.S.)
| | - Lisa A. Gebhardt
- Institute of Physiology and Pathophysiology, University of Erlangen-Nuernberg, 91054 Erlangen, Germany; (L.A.G.); (M.J.M.F.)
| | - Lucas Kreiss
- Department of Medicine I, University Clinics Erlangen, 91054 Erlangen, Germany;
- Institute of Medical Biotechnology, University of Erlangen-Nuernberg, 91052 Erlangen, Germany;
| | - Christin Schneider
- Emil-Fischer-Center, Institute of Biochemistry, University of Erlangen-Nuernberg, 91054 Erlangen, Germany; (T.Z.); (C.S.)
| | - Stephanie Arndt
- Department of Dermatology, University Hospital of Regensburg, 93053 Regensburg, Germany; (S.A.); (S.K.)
| | - Sigrid Karrer
- Department of Dermatology, University Hospital of Regensburg, 93053 Regensburg, Germany; (S.A.); (S.K.)
| | - Oliver Friedrich
- Institute of Medical Biotechnology, University of Erlangen-Nuernberg, 91052 Erlangen, Germany;
| | - Michael J. M. Fischer
- Institute of Physiology and Pathophysiology, University of Erlangen-Nuernberg, 91054 Erlangen, Germany; (L.A.G.); (M.J.M.F.)
- Institute of Physiology, Medical University of Vienna, 1090 Vienna, Austria
| | - Anja-Katrin Bosserhoff
- Emil-Fischer-Center, Institute of Biochemistry, University of Erlangen-Nuernberg, 91054 Erlangen, Germany; (T.Z.); (C.S.)
- Comprehensive Cancer Center (CCC) Erlangen-EMN, 91054 Erlangen, Germany
- Correspondence:
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12
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Copper(II) Complexes with Tetradentate Piperazine-Based Ligands: DNA Cleavage and Cytotoxicity. INORGANICS 2021. [DOI: 10.3390/inorganics9020012] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Five-coordinate Cu(II) complexes, [Cu(Ln)X]ClO4/PF6, where Ln = piperazine ligands bearing two pyridyl arms and X = ClO4− for Ln = L1 (1-ClO4), L2 (2-ClO4), L3 (3-ClO4), and L6 (6-ClO4) as well as [Cu(Ln)Cl]PF6 for Ln = L1 (1-Cl), L4 (4-Cl), and L5 (5-Cl) have been synthesized and characterized by spectroscopic techniques. The molecular structures of the last two complexes were determined by X-ray crystallography. In aqueous acetonitrile solutions, molar conductivity measurements and UV-VIS spectrophotometric titrations of the complexes revealed the hydrolysis of the complexes to [Cu(Ln)(H2O)]2+ species. The biological activity of the Cu(II) complexes with respect to DNA cleavage and cytotoxicity was investigated. At micromolar concentration within 2 h and pH 7.4, DNA cleavage rate decreased in the order: 1-Cl ≈ 1-ClO4 > 3-ClO4 ≥ 2-ClO4 with cleavage enhancements of up to 23 million. Complexes 4-Cl, 5-Cl, and 6-ClO4 were inactive. In order to elucidate the cleavage mechanism, the cleavage of bis(4-nitrophenyl)phosphate (BNPP) and reactive oxygen species (ROS) quenching studies were conducted. The mechanistic pathway of DNA cleavage depends on the ligand’s skeleton: while an oxidative pathway was preferable for 1-Cl/1-ClO4, DNA cleavage by 2-ClO4 and 3-ClO4 predominantly proceeds via a hydrolytic mechanism. Complexes 1-ClO4, 3-ClO4, and 5-Cl were found to be cytotoxic against A2780 cells (IC50 30–40 µM). In fibroblasts, the IC50 value was much higher for 3-ClO4 with no toxic effect.
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13
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Henriksen JR, Engel TB, Petersen AL, Kempen PJ, Melander F, Roos P, Jølck RI, Andresen TL. Elucidating the anomalous membrane permeability of Ag(I), Cu(II), Zn(II) and Au(III) towards new nanoreactor strategies for synthesizing metal nanoparticles. NANOSCALE 2020; 12:22298-22306. [PMID: 33146209 DOI: 10.1039/d0nr04655h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The main structural element defining the cell is the lipid membrane, which is an integral part of regulating the fluxes of ion and nutrition molecules in and out of the cell. Surprisingly, copper ions were found to have anomalous membrane permeability. This led us to consider a broader spectrum of cations and further a new approach for using liposomes as nanoreactors for synthesis of metal and metal alloy nanoparticles. In the present study, the high membrane permeability of Cu2+ and its neighbouring transition elements in the periodic table was investigated. The permeability of Ni2+, Cu2+, Zn2+, Ag+, Au3+, Mg2+, Ca2+ and Lu3+ was assessed, and we report that Zn2+, Cu2+, Ag+ and Au3+ surprisingly are able to cross lipid bilayers. This knowledge is highly relevant for understanding trafficking of cations in biological systems, as well as for design of novel nanoparticle and nanoreactor systems. An example of its use is presented as a platform for synthesizing single highly uniform gold nanoparticles inside liposomal nanoreactors. We envision that this approach could provide a new nanoreactor methodology for forming highly structurally constrained uniform metal and metal alloy nanoparticles, as well as new methods for in vivo tracking of liposomes.
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Affiliation(s)
- Jonas R Henriksen
- Department of Health Technology, Technical University of Denmark, Building 423, DK-2800 Lyngby, Denmark.
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14
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Bopitiya D, Christensen D, Martin M, Zhang J, Bennett LE. Production of hydrogen peroxide in formulated beverages is associated with the presence of ascorbic acid combined with selected redox-active functional ingredients. Food Chem 2020; 338:127947. [PMID: 32947120 DOI: 10.1016/j.foodchem.2020.127947] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/13/2020] [Accepted: 08/24/2020] [Indexed: 12/27/2022]
Abstract
Hydrogen peroxide (H2O2) is a reactive oxygen species (ROS) that mediates essential signaling in vivo but may cause irreversible tissue damage under dysregulated or acute exposure conditions. Beverages containing redox-active compounds might produce H2O2 during shelf storage and potentially be consumed. Concentrations of H2O2 in selected 'functional' (including energy, E, n = 28), 'non-functional' flavored, (S, n = 6) and mineral water (W, n = 6) drinks were measured under ambient (i.e., produced in situ) and 'potentiated' conditions (i.e., H2O2 production enhanced by addition of a reducing agent, to simulate availability of reducible substrates in vivo). Under air-saturated conditions, mean H2O2 contents were: 15.60 ± 15.84; 1.39 ± 2.06 and 0.30 ± 0.21 µM in E, S and W drinks, respectively. Under air-saturated, potentiated conditions, mean rates of H2O2 production were 21.7 ± 33.3, 0.98 ± 2.84, and -0.38 ± 1.18 µM/h for E, S and W drinks, respectively. Using multivariate statistics, the ingredient significantly associated with H2O2 production in combination with other ingredients was found to be ascorbic acid.
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Affiliation(s)
- Dilini Bopitiya
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Dale Christensen
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Miguela Martin
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Jie Zhang
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Louise E Bennett
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia.
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15
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Walter M, Schenkeveld WDC, Geroldinger G, Gille L, Reissner M, Kraemer SM. Identifying the reactive sites of hydrogen peroxide decomposition and hydroxyl radical formation on chrysotile asbestos surfaces. Part Fibre Toxicol 2020; 17:3. [PMID: 31959185 PMCID: PMC6971994 DOI: 10.1186/s12989-019-0333-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/23/2019] [Indexed: 12/02/2022] Open
Abstract
Background Fibrous chrysotile has been the most commonly applied asbestos mineral in a range of technical applications. However, it is toxic and carcinogenic upon inhalation. The chemical reactivity of chrysotile fiber surfaces contributes to its adverse health effects by catalyzing the formation of highly reactive hydroxyl radicals (HO•) from H2O2. In this Haber-Weiss cycle, Fe on the fiber surface acts as a catalyst: Fe3+ decomposes H2O2 to reductants that reduce surface Fe3+ to Fe2+, which is back-oxidized by H2O2 (Fenton-oxidation) to yield HO•. Chrysotile contains three structural Fe species: ferrous and ferric octahedral Fe and ferric tetrahedral Fe (Fe3+tet). Also, external Fe may adsorb or precipitate onto fiber surfaces. The goal of this study was to identify the Fe species on chrysotile surfaces that catalyze H2O2 decomposition and HO• generation. Results We demonstrate that at the physiological pH 7.4 Fe3+tet on chrysotile surfaces substantially contributes to H2O2 decomposition and is the key structural Fe species catalyzing HO• generation. After depleting Fe from fiber surfaces, a remnant fiber-related H2O2 decomposition mode was identified, which may involve magnetite impurities, remnant Fe or substituted redox-active transition metals other than Fe. Fe (hydr)oxide precipitates on chrysotile surfaces also contributed to H2O2 decomposition, but were per mole Fe substantially less efficient than surface Fe3+tet. Fe added to chrysotile fibers increased HO• generation only when it became incorporated and tetrahedrally coordinated into vacancy sites in the Si layer. Conclusions Our results suggest that at the physiological pH 7.4, oxidative stress caused by chrysotile fibers largely results from radicals produced in the Haber-Weiss cycle that is catalyzed by Fe3+tet. The catalytic role of Fe3+tet in radical generation may also apply to other pathogenic silicates in which Fe3+tet is substituted, e.g. quartz, amphiboles and zeolites. However, even if these pathogenic minerals do not contain Fe, our results suggest that the mere presence of vacancy sites may pose a risk, as incorporation of external Fe into a tetrahedral coordination environment can lead to HO• generation.
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Affiliation(s)
- Martin Walter
- Department of Environmental Geosciences, University of Vienna, Althanstraße 14 (UZA II), 1090, Vienna, Austria
| | - Walter D C Schenkeveld
- Department of Environmental Geosciences, University of Vienna, Althanstraße 14 (UZA II), 1090, Vienna, Austria. .,Copernicus Institute of Sustainable Development, Faculty of Geosciences, Utrecht University, Princetonlaan 8A, 3584, CB, Utrecht, the Netherlands.
| | - Gerald Geroldinger
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Lars Gille
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
| | - Michael Reissner
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040, Vienna, Austria
| | - Stephan M Kraemer
- Department of Environmental Geosciences, University of Vienna, Althanstraße 14 (UZA II), 1090, Vienna, Austria
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16
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Schneider C, Gebhardt L, Arndt S, Karrer S, Zimmermann JL, Fischer MJM, Bosserhoff AK. Acidification is an Essential Process of Cold Atmospheric Plasma and Promotes the Anti-Cancer Effect on Malignant Melanoma Cells. Cancers (Basel) 2019; 11:cancers11050671. [PMID: 31091795 PMCID: PMC6562457 DOI: 10.3390/cancers11050671] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/04/2019] [Accepted: 05/08/2019] [Indexed: 12/11/2022] Open
Abstract
(1) Background: Cold atmospheric plasma (CAP) is ionized gas near room temperature. The anti-cancer effects of CAP were confirmed for several cancer types and were attributed to CAP-induced reactive species. However, the mode of action of CAP is still not well understood. (2) Methods: Changes in cytoplasmic Ca2+ level after CAP treatment of malignant melanoma cells were analyzed via the intracellular Ca2+ indicator fura-2 AM. CAP-produced reactive species were determined by fluorescence spectroscopic and protein nitration by Western Blot analysis. (3) Results: CAP caused a strong acidification of water and solutions that were buffered with the so-called Good buffers, while phosphate-buffered solutions with higher buffer capacity showed minor pH reductions. The CAP-induced Ca2+ influx in melanoma cells was stronger in acidic pH than in physiological conditions. NO formation that is induced by CAP was dose- and pH-dependent and CAP-treated solutions only caused protein nitration in cells under acidic conditions. (4) Conclusions: We describe the impact of CAP-induced acidification on the anti-cancer effects of CAP. A synergistic effect of CAP-induced ROS, RNS, and acidic conditions affected the intracellular Ca2+ level of melanoma cells. As the microenvironment of tumors is often acidic, further acidification might be one reason for the specific anti-cancer effects of CAP.
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Affiliation(s)
- Christin Schneider
- Institute of Biochemistry, Emil-Fischer-Center, University of Erlangen-Nürnberg, 91054 Erlangen, Germany.
| | - Lisa Gebhardt
- Institute of Physiology and Pathophysiology, University of Erlangen-Nürnberg, 91054 Erlangen, Germany.
| | - Stephanie Arndt
- Department of Dermatology, University Hospital Regensburg, 93053 Regensburg, Germany.
| | - Sigrid Karrer
- Department of Dermatology, University Hospital Regensburg, 93053 Regensburg, Germany.
| | | | - Michael J M Fischer
- Institute of Physiology and Pathophysiology, University of Erlangen-Nürnberg, 91054 Erlangen, Germany.
- Institute of Physiology, Medical University of Vienna, 1090 Vienna, Austria.
| | - Anja-Katrin Bosserhoff
- Institute of Biochemistry, Emil-Fischer-Center, University of Erlangen-Nürnberg, 91054 Erlangen, Germany.
- Comprehensive Cancer Center (CCC) Erlangen-EMN, 91054 Erlangen, Germany.
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17
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Kuo CT, Wu IC, Chen L, Yu J, Wu L, Chiu DT. Improving the Photostability of Semiconducting Polymer Dots Using Buffers. Anal Chem 2018; 90:11785-11790. [PMID: 30277754 DOI: 10.1021/acs.analchem.8b03104] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The photostability of fluorescent probes is critical in biological imaging, especially for long-term observational analyses. Here, we describe a simple and universal method to improve the photostability of semiconducting polymer dots (Pdots) and other fluorescent probes by using buffers. Using Pdots as a model system, we found that HEPES or MES buffer can improve the photostability of Pdots by a factor of 20. Through a systematic study, we show that Pdot photobleaching is dominated by photoinduced radicals which can be quenched by the piperazine or morpholine structures of these buffers, which act as radical scavengers. For conditions where choice of buffer is limited, we designed fluorescent polymers conjugated with radical scavengers to improve Pdot photostability. We then demonstrate a practical application in which HEPES buffer is used to improve the photostability of Pdots during cell imaging.
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Affiliation(s)
- Chun-Ting Kuo
- Departments of Chemistry and Bioengineering , University of Washington , Seattle , Washington 98195 , United States
| | - I-Che Wu
- Departments of Chemistry and Bioengineering , University of Washington , Seattle , Washington 98195 , United States
| | - Lei Chen
- Departments of Chemistry and Bioengineering , University of Washington , Seattle , Washington 98195 , United States
| | - Jiangbo Yu
- Departments of Chemistry and Bioengineering , University of Washington , Seattle , Washington 98195 , United States
| | - Li Wu
- Departments of Chemistry and Bioengineering , University of Washington , Seattle , Washington 98195 , United States
| | - Daniel T Chiu
- Departments of Chemistry and Bioengineering , University of Washington , Seattle , Washington 98195 , United States
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18
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Tiwari MK, Leinisch F, Sahin C, Møller IM, Otzen DE, Davies MJ, Bjerrum MJ. Early events in copper-ion catalyzed oxidation of α-synuclein. Free Radic Biol Med 2018; 121:38-50. [PMID: 29689296 DOI: 10.1016/j.freeradbiomed.2018.04.559] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/28/2018] [Accepted: 04/17/2018] [Indexed: 12/11/2022]
Abstract
Previous studies on metal-ion catalyzed oxidation of α-synuclein oxidation have mostly used conditions that result in extensive modification precluding an understanding of the early events in this process. In this study, we have examined time-dependent oxidative events related to α-synuclein modification using six different molar ratios of Cu2+/H2O2/protein and Cu2+/H2O2/ascorbate/protein resulting in mild to moderate extents of oxidation. For a Cu2+/H2O2/protein molar ratio of 2.3:7.8:1 only low levels of carbonyls were detected (0.078 carbonyls per protein), whereas a molar ratio of 4.7:15.6:1 gave 0.22 carbonyls per α-synuclein within 15 min. With the latter conditions, rapid conversion of 3 out of 4 methionines (Met) to methionine sulfoxide, and 2 out of 4 tyrosines (Tyr) were converted to products including inter- and intra-molecular dityrosine cross-links and protein oligomers, as determined by SDS-PAGE and Western blot analysis. Limited histidine (His) modification was observed. The rapid formation of dityrosine cross-links was confirmed by fluorescence and mass-spectrometry. These data indicate that Met and Tyr oxidation are early events in Cu2+/H2O2-mediated damage, with carbonyl formation being a minor process. With the Cu2+/H2O2/ascorbate system, rapid protein carbonyl formation was detected with the first 5 min, but after this time point, little additional carbonyl formation was detected. With this system, lower levels of Met and Tyr oxidation were detected (2 Met and 1 Tyr modified with a Cu2+/H2O2/ascorbate/protein ratio of 2.3:7.8:7.8:1), but greater His oxidation. Only low levels of intra- dityrosine cross-links and no inter- dityrosine oligomers were detected under these conditions, suggesting that ascorbate limits Cu2+/H2O2-induced α-synuclein modification.
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Affiliation(s)
- Manish K Tiwari
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Fabian Leinisch
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cagla Sahin
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Ian Max Møller
- Department of Molecular Biology and Genetics, Aarhus University, Slagelse, Denmark
| | - Daniel E Otzen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Michael J Davies
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten J Bjerrum
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark.
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Soldatova AV, Tao L, Romano CA, Stich TA, Casey WH, Britt RD, Tebo BM, Spiro TG. Mn(II) Oxidation by the Multicopper Oxidase Complex Mnx: A Binuclear Activation Mechanism. J Am Chem Soc 2017; 139:11369-11380. [PMID: 28712284 DOI: 10.1021/jacs.7b02771] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The bacterial protein complex Mnx contains a multicopper oxidase (MCO) MnxG that, unusually, catalyzes the two-electron oxidation of Mn(II) to MnO2 biomineral, via a Mn(III) intermediate. Although Mn(III)/Mn(II) and Mn(IV)/Mn(III) reduction potentials are expected to be high, we find a low reduction potential, 0.38 V (vs Normal Hydrogen Electrode, pH 7.8), for the MnxG type 1 Cu2+, the electron acceptor. Indeed the type 1 Cu2+ is not reduced by Mn(II) in the absence of molecular oxygen, indicating that substrate oxidation requires an activation step. We have investigated the enzyme mechanism via electronic absorption spectroscopy, using chemometric analysis to separate enzyme-catalyzed MnO2 formation from MnO2 nanoparticle aging. The nanoparticle aging time course is characteristic of nucleation and particle growth; rates for these processes followed expected dependencies on Mn(II) concentration and temperature, but exhibited different pH optima. The enzymatic time course is sigmoidal, signaling an activation step, prior to turnover. The Mn(II) concentration and pH dependence of a preceding lag phase indicates weak Mn(II) binding. The activation step is enabled by a pKa > 8.6 deprotonation, which is assigned to Mn(II)-bound H2O; it induces a conformation change (consistent with a high activation energy, 106 kJ/mol) that increases Mn(II) affinity. Mnx activation is proposed to decrease the Mn(III/II) reduction potential below that of type 1 Cu(II/I) by formation of a hydroxide-bridged binuclear complex, Mn(II)(μ-OH)Mn(II), at the substrate site. Turnover is found to depend cooperatively on two Mn(II) and is enabled by a pKa 7.6 double deprotonation. It is proposed that turnover produces a Mn(III)(μ-OH)2Mn(III) intermediate that proceeds to the enzyme product, likely Mn(IV)(μ-O)2Mn(IV) or an oligomer, which subsequently nucleates MnO2 nanoparticles. We conclude that Mnx exploits manganese polynuclear chemistry in order to facilitate an otherwise difficult oxidation reaction, as well as biomineralization. The mechanism of the Mn(III/IV) conversion step is elucidated in an accompanying paper .
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Affiliation(s)
- Alexandra V Soldatova
- Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195, United States
| | | | - Christine A Romano
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University , Portland, Oregon 97239, United States
| | | | | | | | - Bradley M Tebo
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University , Portland, Oregon 97239, United States
| | - Thomas G Spiro
- Department of Chemistry, University of Washington , Box 351700, Seattle, Washington 98195, United States
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20
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Mehlenbacher M, Poli M, Arosio P, Santambrogio P, Levi S, Chasteen ND, Bou-Abdallah F. Iron Oxidation and Core Formation in Recombinant Heteropolymeric Human Ferritins. Biochemistry 2017. [PMID: 28636371 DOI: 10.1021/acs.biochem.7b00024] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In animals, the iron storage and detoxification protein, ferritin, is composed of two functionally and genetically distinct subunit types, H (heavy) and L (light), which co-assemble in various ratios with tissue specific distributions to form shell-like protein structures of 24 subunits within which a mineralized iron core is stored. The H-subunit possesses a ferroxidase center (FC) that catalyzes Fe(II) oxidation, whereas the L-subunit does not. To assess the role of the L-subunit in iron oxidation and core formation, two human recombinant heteropolymeric ferritins, designated H-rich and L-rich with ratios of ∼20H:4L and ∼22L:2H, respectively, were employed and compared to the human homopolymeric H-subunit ferritin (HuHF). These heteropolymeric ferritins have a composition similar to the composition of those found in hearts and brains (i.e., H-rich) and in livers and spleens (i.e., L-rich). As for HuHF, iron oxidation in H-rich ferritin was found to proceed with a 2:1 Fe(II):O2 stoichiometry at an iron level of 2 Fe(II) atoms/H-subunit with the generation of H2O2. The H2O2 reacted with additional Fe(II) in a 2:1 Fe(II):H2O2 ratio, thus avoiding the production of hydroxyl radical. A μ-1,2-peroxo-diFe(III) intermediate was observed at the FC of H-rich ferritin as for HuHF. Importantly, the H-rich protein regenerated full ferroxidase activity more rapidly than HuHF did and additionally formed larger iron cores, indicating dual roles for the L-subunit in facilitating iron turnover at the FC and in mineralization of the core. The L-rich ferritin, while also facilitating iron oxidation at the FC, additionally promoted oxidation at the mineral surface once the iron binding capacity of the FC was exceeded.
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Affiliation(s)
- Matthew Mehlenbacher
- Department of Chemistry, State University of New York , Potsdam, New York 13676, United States
| | - Maura Poli
- Department of Molecular and Translational Medicine, University of Brescia , 25121 Brescia, Italy
| | - Paolo Arosio
- Department of Molecular and Translational Medicine, University of Brescia , 25121 Brescia, Italy
| | | | | | - N Dennis Chasteen
- Department of Chemistry, University of New Hampshire , Durham, New Hampshire 03824, United States
| | - Fadi Bou-Abdallah
- Department of Chemistry, State University of New York , Potsdam, New York 13676, United States
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21
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Tao L, Stich TA, Liou SH, Soldatova AV, Delgadillo DA, Romano CA, Spiro TG, Goodin DB, Tebo BM, Casey WH, Britt RD. Copper Binding Sites in the Manganese-Oxidizing Mnx Protein Complex Investigated by Electron Paramagnetic Resonance Spectroscopy. J Am Chem Soc 2017; 139:8868-8877. [DOI: 10.1021/jacs.7b02277] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | | | | | - Alexandra V. Soldatova
- Department
of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195, United States
| | - David A. Delgadillo
- Department of Chemistry & Chemical Biology, University of California, 5200 North Lake Road, Merced, California 95343, United States
| | - Christine A. Romano
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Thomas G. Spiro
- Department
of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195, United States
| | | | - Bradley M. Tebo
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University, Portland, Oregon 97239, United States
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22
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Alonso-de Castro S, Ruggiero E, Ruiz-de-Angulo A, Rezabal E, Mareque-Rivas JC, Lopez X, López-Gallego F, Salassa L. Riboflavin as a bioorthogonal photocatalyst for the activation of a Pt IV prodrug. Chem Sci 2017; 8:4619-4625. [PMID: 28626570 PMCID: PMC5471451 DOI: 10.1039/c7sc01109a] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 04/13/2017] [Indexed: 12/12/2022] Open
Abstract
Encouraging developments demonstrate that few transition metal and organometallic catalysts can operate in a bioorthogonal fashion and promote non-natural chemistry in living systems by minimizing undesired side reactions with cellular components. These catalytic processes have potential for applications in medicinal chemistry and chemical biology. However, the stringent conditions of the cell environment severely limit the number of accessible metal catalysts and exogenous reactions. Herein, we report an unorthodox approach and a new type of bioorthogonal catalytic reaction, in which a metal complex is an unconventional substrate and an exogenous biological molecule acts as a catalyst. In this reaction, riboflavin photocatalytically converts a PtIV prodrug into cisplatin within the biological environment. Due to the catalytic activity of riboflavin, cisplatin-like apoptosis is induced in cancer cells under extremely low doses of light, potentially preventing systemic off-target reactions. Photocatalytic and bioorthogonal turnover of PtIV into PtII species is an attractive strategy to amplify the antineoplastic action of metal-based chemotherapeutics with spatio-temporal control.
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Affiliation(s)
| | - Emmanuel Ruggiero
- CIC biomaGUNE , Paseo de Miramón 182 , Donostia-San Sebastián , 20014 , Spain
| | - Ane Ruiz-de-Angulo
- CIC biomaGUNE , Paseo de Miramón 182 , Donostia-San Sebastián , 20014 , Spain
| | - Elixabete Rezabal
- Farmazia Fakultatea , Kimika Fisikoa Departamentua , Euskal Herriko Unibertsitatea , UPV/EHU , 01006 , Vitoria-Gasteiz , Spain
- Donostia International Physics Center (DIPC) , P.K. 1072 , Donostia-San Sebastián , 20080 , Spain
| | - Juan C Mareque-Rivas
- CIC biomaGUNE , Paseo de Miramón 182 , Donostia-San Sebastián , 20014 , Spain
- Ikerbasque , Basque Foundation for Science , Bilbao , 48011 , Spain
| | - Xabier Lopez
- Donostia International Physics Center (DIPC) , P.K. 1072 , Donostia-San Sebastián , 20080 , Spain
- Kimika Fakultatea , Euskal Herriko Unibertsitatea , UPV/EHU , Donostia-San Sebastián 20080 , Spain .
| | - Fernando López-Gallego
- CIC biomaGUNE , Paseo de Miramón 182 , Donostia-San Sebastián , 20014 , Spain
- Ikerbasque , Basque Foundation for Science , Bilbao , 48011 , Spain
| | - Luca Salassa
- CIC biomaGUNE , Paseo de Miramón 182 , Donostia-San Sebastián , 20014 , Spain
- Donostia International Physics Center (DIPC) , P.K. 1072 , Donostia-San Sebastián , 20080 , Spain
- Ikerbasque , Basque Foundation for Science , Bilbao , 48011 , Spain
- Kimika Fakultatea , Euskal Herriko Unibertsitatea , UPV/EHU , Donostia-San Sebastián 20080 , Spain .
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23
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Xu X, Gevaert B, Bracke N, Yao H, Wynendaele E, De Spiegeleer B. Hydrophilic interaction liquid chromatography method development and validation for the assay of HEPES zwitterionic buffer. J Pharm Biomed Anal 2016; 135:227-233. [PMID: 27993432 DOI: 10.1016/j.jpba.2016.11.054] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/22/2016] [Accepted: 11/29/2016] [Indexed: 11/30/2022]
Abstract
HEPES is a zwitterionic buffer component used as a raw material in the GMP-manufacturing of advanced therapy medicinal products (ATMPs), hence requiring an adequate assay method with sufficient selectivity toward related impurities. Therefore, a hydrophilic interaction chromatography (HILIC) method was developed. Different factors were investigated towards the retention behavior of HEPES, its analogue EPPS and its starting material isethionate: pH, ion concentration and organic solvent ratio of the mobile phase, as well as column temperature. Moreover, stress testing resulted in the N-oxide degradant, identified by high resolution MS. The final method consisted of an isocratic system with an aqueous (pH 2.0 with H3PO4) acetonitrile (35:65, v/v) mobile phase on a zwitterionic HILIC (Obelisc N) column with a flow rate of 0.5mL/min and UV detection at 195nm. The assay method of HEPES was validated, obtaining adequate linearity (R2=0.999), precision (RSD of 0.5%) and accuracy (recovery of 100.08%). Finally, the applicability of the validated method was demonstrated by analysis of samples from different suppliers.
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Affiliation(s)
- Xiaolong Xu
- Drug Quality and Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Bert Gevaert
- Drug Quality and Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Nathalie Bracke
- Drug Quality and Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Han Yao
- Drug Quality and Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Evelien Wynendaele
- Drug Quality and Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Bart De Spiegeleer
- Drug Quality and Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium.
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24
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Zbacnik TJ, Holcomb RE, Katayama DS, Murphy BM, Payne RW, Coccaro RC, Evans GJ, Matsuura JE, Henry CS, Manning MC. Role of Buffers in Protein Formulations. J Pharm Sci 2016; 106:713-733. [PMID: 27894967 DOI: 10.1016/j.xphs.2016.11.014] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 10/25/2016] [Accepted: 11/17/2016] [Indexed: 12/19/2022]
Abstract
Buffers comprise an integral component of protein formulations. Not only do they function to regulate shifts in pH, they also can stabilize proteins by a variety of mechanisms. The ability of buffers to stabilize therapeutic proteins whether in liquid formulations, frozen solutions, or the solid state is highlighted in this review. Addition of buffers can result in increased conformational stability of proteins, whether by ligand binding or by an excluded solute mechanism. In addition, they can alter the colloidal stability of proteins and modulate interfacial damage. Buffers can also lead to destabilization of proteins, and the stability of buffers themselves is presented. Furthermore, the potential safety and toxicity issues of buffers are discussed, with a special emphasis on the influence of buffers on the perceived pain upon injection. Finally, the interaction of buffers with other excipients is examined.
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Affiliation(s)
| | - Ryan E Holcomb
- LegacyBioDesign LLC, Johnstown, Colorado 80534; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | - Derrick S Katayama
- LegacyBioDesign LLC, Johnstown, Colorado 80534; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | - Brian M Murphy
- LegacyBioDesign LLC, Johnstown, Colorado 80534; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | - Robert W Payne
- LegacyBioDesign LLC, Johnstown, Colorado 80534; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | | | | | | | - Charles S Henry
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523
| | - Mark Cornell Manning
- LegacyBioDesign LLC, Johnstown, Colorado 80534; Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523.
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25
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Brown KA, Harris DF, Wilker MB, Rasmussen A, Khadka N, Hamby H, Keable S, Dukovic G, Peters JW, Seefeldt LC, King PW. Light-driven dinitrogen reduction catalyzed by a CdS:nitrogenase MoFe protein biohybrid. Science 2016; 352:448-50. [PMID: 27102481 DOI: 10.1126/science.aaf2091] [Citation(s) in RCA: 397] [Impact Index Per Article: 49.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 03/23/2016] [Indexed: 01/24/2023]
Abstract
The splitting of dinitrogen (N2) and reduction to ammonia (NH3) is a kinetically complex and energetically challenging multistep reaction. In the Haber-Bosch process, N2 reduction is accomplished at high temperature and pressure, whereas N2 fixation by the enzyme nitrogenase occurs under ambient conditions using chemical energy from adenosine 5'-triphosphate (ATP) hydrolysis. We show that cadmium sulfide (CdS) nanocrystals can be used to photosensitize the nitrogenase molybdenum-iron (MoFe) protein, where light harvesting replaces ATP hydrolysis to drive the enzymatic reduction of N2 into NH3 The turnover rate was 75 per minute, 63% of the ATP-coupled reaction rate for the nitrogenase complex under optimal conditions. Inhibitors of nitrogenase (i.e., acetylene, carbon monoxide, and dihydrogen) suppressed N2 reduction. The CdS:MoFe protein biohybrids provide a photochemical model for achieving light-driven N2 reduction to NH3.
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Affiliation(s)
- Katherine A Brown
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Derek F Harris
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Molly B Wilker
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Andrew Rasmussen
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Nimesh Khadka
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Hayden Hamby
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Stephen Keable
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Gordana Dukovic
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA
| | - John W Peters
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Lance C Seefeldt
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322, USA
| | - Paul W King
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.
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26
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Ferreira CMH, Pinto ISS, Soares EV, Soares HMVM. (Un)suitability of the use of pH buffers in biological, biochemical and environmental studies and their interaction with metal ions – a review. RSC Adv 2015. [DOI: 10.1039/c4ra15453c] [Citation(s) in RCA: 189] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The present work reviews, discusses and update the metal complexation characteristics of thirty one buffers commercially available. Additionally, their impact on the biological systems is also presented and discussed.
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Affiliation(s)
- Carlos M. H. Ferreira
- REQUIMTE/LAQV
- Department of Chemical Engineering
- Faculty of Engineering
- University of Porto
- Porto
| | - Isabel S. S. Pinto
- REQUIMTE/LAQV
- Department of Chemical Engineering
- Faculty of Engineering
- University of Porto
- Porto
| | - Eduardo V. Soares
- Bioengineering Laboratory
- Chemical Engineering Department
- ISEP-School of Engineering of Polytechnic Institute of Porto
- Porto
- Portugal
| | - Helena M. V. M. Soares
- REQUIMTE/LAQV
- Department of Chemical Engineering
- Faculty of Engineering
- University of Porto
- Porto
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27
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Đurović MD, Bugarčić ŽD, Heinemann FW, van Eldik R. Substitution versus redox reactions of gold(iii) complexes with l-cysteine, l-methionine and glutathione. Dalton Trans 2014; 43:3911-21. [DOI: 10.1039/c3dt53140f] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions of [AuCl4]−, [Au(terpy)Cl]2+, [Au(bpma)Cl]2+ and [Au(dien)Cl]2+ with l-cysteine, l-methionine and glutathione were examined using stopped-flow, cyclovoltammetry, 1H NMR and ESI-MS techniques.
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Affiliation(s)
| | | | - Frank W. Heinemann
- Inorganic Chemistry
- Department of Chemistry and Pharmacy
- University of Erlangen-Nürnberg
- 91058 Erlangen, Germany
| | - Rudi van Eldik
- Inorganic Chemistry
- Department of Chemistry and Pharmacy
- University of Erlangen-Nürnberg
- 91058 Erlangen, Germany
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28
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Electrodynamics of lipid membrane interactions in the presence of zwitterionic buffers. Biophys J 2011; 101:362-9. [PMID: 21767488 DOI: 10.1016/j.bpj.2011.05.062] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 05/10/2011] [Accepted: 05/27/2011] [Indexed: 11/22/2022] Open
Abstract
Due to thermal motion and molecular polarizability, electrical interactions in biological systems have a dynamic character. Zwitterions are dipolar molecules that typically are highly polarizable and exhibit both a positive and a negative charge depending on the pH of the solution. We use multilamellar structures of common lipids to identify and quantify the effects of zwitterionic buffers that go beyond the control of pH. We use the fact that the repeat spacing of multilamellar lipid bilayers is a sensitive and accurate indicator of the force balance between membranes. We show that common buffers can in fact charge up neutral membranes. However, this electrostatic effect is not immediately recognized because of the concomitant modification of dispersion (van der Waals) forces. We show that although surface charging can be weak, electrostatic forces are significant even at large distances because of reduced ionic screening and reduced van der Waals attraction. The zwitterionic interactions that we identify are expected to be relevant for interfacial biological processes involving lipid bilayers, and for a wide range of biomaterials, including amino acids, detergents, and pharmaceutical drugs. An appreciation of zwitterionic electrodynamic character can lead to a better understanding of molecular interactions in biological systems and in soft materials in general.
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29
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Taha M, Gupta BS, Khoiroh I, Lee MJ. Interactions of Biological Buffers with Macromolecules: The Ubiquitous “Smart” Polymer PNIPAM and the Biological Buffers MES, MOPS, and MOPSO. Macromolecules 2011. [DOI: 10.1021/ma201790c] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mohamed Taha
- Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106-07, Taiwan
| | - Bhupender S. Gupta
- Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106-07, Taiwan
| | - Ianatul Khoiroh
- Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106-07, Taiwan
| | - Ming-Jer Lee
- Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106-07, Taiwan
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30
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Das AK, Raj CR. Rapid room temperature synthesis of electrocatalytically active Au nanostructures. J Colloid Interface Sci 2011; 353:506-11. [DOI: 10.1016/j.jcis.2010.09.080] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 09/07/2010] [Accepted: 09/25/2010] [Indexed: 11/29/2022]
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31
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Heller MI, Croot PL. Application of a superoxide (O(2)(-)) thermal source (SOTS-1) for the determination and calibration of O(2)(-) fluxes in seawater. Anal Chim Acta 2010; 667:1-13. [PMID: 20441861 DOI: 10.1016/j.aca.2010.03.054] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 03/17/2010] [Accepted: 03/25/2010] [Indexed: 11/17/2022]
Abstract
Superoxide (O(2)(-)) is an important short lived transient reactive oxygen species (ROS) in seawater. The main source of O(2)(-) in the ocean is believed to be through photochemical reactions though biological processes may also be important. Sink terms for O(2)(-) include redox reactions with bioactive trace metals, including Cu and Fe, and to a lesser extent dissolved organic matter (DOM). Information on the source fluxes, sinks and concentration of superoxide in the open ocean are crucial to improving our understanding of the biogeochemical cycling of redox active species. As O(2)(-) is a highly reactive transient species present at low concentrations it is not a trivial task to make accurate and precise measurements in seawater. In this study we developed the appropriate numerical analysis tools and investigated a number of superoxide sources and methods for the purposes of calibrating O(2)(-) concentrations and/or fluxes specifically in seawater. We found the superoxide thermal source bis(4-carboxybenzyl)hyponitrite (SOTS)-1 easy to employ as a reliable source of O(2)(-) which could be successfully applied in seawater. The thermal decomposition of SOTS-1 in seawater was evaluated over a range of seawater temperatures using both a flux based detection scheme developed using two spectrophotometric methods: (i) 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) and (ii) ferricytochrome c (FC), or a concentration based detection scheme using a chemiluminescence flow injection method based on the Cypridina luciferin analog 2-methyl-6-(p-methoxyphenyl)3-7-dihydroimidazol[1,2-alpha]pyrazin-3-one (MCLA) as reagent. Our results suggest SOTS-1 is the best available O(2)(-) source for determining concentrations and fluxes, all detection systems tested have their pros and cons and the choice of which to use depends more on the duration and type of experiment that is required.
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Affiliation(s)
- M I Heller
- FB2 Marine Biogeochemie, Leibniz-Institut für Meereswissenschaften (IfM-Geomar), Dienstgebäude Westufer, Düsternbrooker Weg 20, 24105 Kiel, Germany
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32
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Lee JH, Kim SB, Park C, Kim SW. Effect of a buffer mixture system on the activity of lipases during immobilization process. BIORESOURCE TECHNOLOGY 2010; 101 Suppl 1:S66-S70. [PMID: 19361984 DOI: 10.1016/j.biortech.2009.03.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2008] [Revised: 02/11/2009] [Accepted: 03/12/2009] [Indexed: 05/27/2023]
Abstract
In this study, the effects of various buffers and ionic strengths on the immobilization of Candida rugosa and Rhizopus oryzae lipases were investigated to enhance the activities of the immobilized lipases. Among the various buffers, the optimal buffers and ionic strength for the immobilization of C. rugosa and R. oryzae lipases were determined to be a mixture of 0.25M MOPs and sodium phosphate buffer (pH 6.5). Moreover, the activities of immobilized C. rugosa and R. oryzae lipases under their optimal conditions were 3756.11 and 2845.21U/g matrix, respectively. Furthermore, the activity of immobilized lipases increased by approximately 4.13 and 3.1 times after 24h, respectively. Finally, the activities of the immobilized lipases were maintained at levels greater than 90% of their original activities after ten reuses and at levels greater than 60% of their original activities after twenty reuses.
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Affiliation(s)
- Jong Ho Lee
- Department of Chemical and Biological Engineering, Korea University, 1 Anam-dong, Sungbuk-ku, Seoul, Republic of Korea.
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33
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Stanley SK, Becker ML, Lin EK, Wu WL. Inhibitory effects of a phage-derived peptide on Au nanocrystal nucleation and growth. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:10886-10892. [PMID: 19630407 DOI: 10.1021/la901222k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Peptides have been shown to mediate the reduction and clustering of inorganic ions during biomineralization processes to build nanomaterials with well-defined shape, size, and composition. This precise control has been linked to specific amino acid sequence; however, there is a lack of information about the role of peptides during mineralization. Here, we investigate the nucleation and growth behavior of Au nanocrystals that are mediated by the engineered peptide AYSSGAPPMPPF. Unlike other nanocrystal synthesis schemes, this peptide produces Au nanocrystals from Au(III) ions at very low relative peptide concentrations, at ambient temperature, and in water at neutral pH. Our data show that (i) the peptide AYSSGAPPMPPF actually inhibits nucleation and growth of nanocrystals, (ii) HEPES plays an active chemical role as the reducing agent, and (iii) HAuCl4 accelerates the kinetics of nanoparticle nucleation and growth. Herein, we propose empirical rate laws for nucleation and growth of Au nanocrystals and compare kinetic rate laws for this peptide, citrate, and various other polymer ligands. We find that the peptide belongs to a unique class of nonreducing inhibitor ligands regulating the surface-reaction-limited growth of nanocrystals.
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Affiliation(s)
- Scott K Stanley
- National Institute of Standards and Technology, Polymers Division 100 Bureau Drive, Gaithersburg, Maryland 20899, USA.
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34
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Engelbrekt C, Sørensen KH, Zhang J, Welinder AC, Jensen PS, Ulstrup J. Green synthesis of gold nanoparticles with starch–glucose and application in bioelectrochemistry. ACTA ACUST UNITED AC 2009. [DOI: 10.1039/b911111e] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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LaButti JN, Gates KS. Biologically relevant chemical properties of peroxymonophosphate (=O3POOH). Bioorg Med Chem Lett 2008; 19:218-21. [PMID: 19022671 DOI: 10.1016/j.bmcl.2008.10.133] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 10/22/2008] [Accepted: 10/27/2008] [Indexed: 11/26/2022]
Abstract
It has been suggested that peroxymonophosphate could serve as an endogenous hydrogen peroxide-derived regulator of cellular protein tyrosine phosphatase activity under physiological or pathophysiological conditions. To facilitate further consideration of the potential role of peroxymonophosphate in biological systems we present studies related to the preparation, characterization, stability, and fluorometric detection of this agent.
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Affiliation(s)
- Jason N LaButti
- Departments of Chemistry and Biochemistry, University of Missouri, 125 Chemistry Building, Columbia, MO 65211, USA
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36
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Zhang B, Wilson PE, Watt GD. Ferritin-catalyzed consumption of hydrogen peroxide by amine buffers causes the variable Fe2+ to O2 stoichiometry of iron deposition in horse spleen ferritin. J Biol Inorg Chem 2006; 11:1075-86. [PMID: 16896807 DOI: 10.1007/s00775-006-0141-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Accepted: 06/27/2006] [Indexed: 11/24/2022]
Abstract
Ferritin catalyzes the oxidation of Fe2+ by O2 to form a reconstituted Fe3+ oxy-hydroxide mineral core, but extensive studies have shown that the Fe2+ to O2 stoichiometry changes with experimental conditions. At Fe2+ to horse spleen ferritin (HoSF) ratios greater than 200, an upper limit of Fe2+ to O2 of 4 is typically measured, indicating O2 is reduced to 2H2O. In contrast, a lower limit of Fe2+ to O2 of approximately 2 is measured at low Fe2+ to HoSF ratios, implicating H2O2 as a product of Fe2+ deposition. Stoichiometric amounts of H2O2 have not been measured, and H2O2 is proposed to react with an unknown system component. Evidence is presented that identifies this component as amine buffers, including 3-N-morpholinopropanesulfonic acid (MOPS), which is widely used in ferritin studies. In the presence of non-amine buffers, the Fe2+ to O2 stoichiometry was approximately 4.0, but at high concentrations of amine buffers (0.10 M) the Fe2+ to O2 stoichiometry is approximately 2.5 for iron loadings of eight to 30 Fe2+ per HoSF. Decreasing the concentration of amine buffer to zero resulted in an Fe2+ to O2 stoichiometry of approximately 4. Direct evidence for amine buffer modification during Fe2+ deposition was obtained by comparing authentic and modified buffers using mass spectrometry, NMR, and thin layer chromatography. Tris(hydroxymethyl)aminomethane, MOPS, and N-methylmorpholine (a MOPS analog) were all rapidly chemically modified during Fe2+ deposition to form N-oxides. Under identical conditions no modification was detected when amine buffer, H2O2, and O2 were combined with Fe2+ or ferritin separately. Thus, a short-lived ferritin intermediate is required for buffer modification by H2O2. Variation of the Fe2+ to O2 stoichiometry versus the Fe2+ to HoSF ratio and the amine buffer concentration are consistent with buffer modification.
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Affiliation(s)
- Bo Zhang
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA
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