1
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Hashmi K, Gupta S, Siddique A, Khan T, Joshi S. Medicinal applications of vanadium complexes with Schiff bases. J Trace Elem Med Biol 2023; 79:127245. [PMID: 37406475 DOI: 10.1016/j.jtemb.2023.127245] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/31/2023] [Accepted: 06/15/2023] [Indexed: 07/07/2023]
Abstract
Many transition metal complexes have been explored for their therapeutic properties after the discovery of cisplatin. Schiff bases have an efficient complexation tendency with the transition metals and several medicinal properties have been reported. However, fewer studies have reported the medicinal utility of vanadium and its Schiff base complexes. This paper provides a comprehensive overview of vanadium complexes with Schiff bases along with their mechanistic insight. Vanadium complexes in + 4 and + 5 oxidation states have exhibited well-defined geometry and found to be thermodynamically stable. The studies have reported the G0/G1 phase cell cycle arrest and decreased delta psi m, inducing mitochondrial membrane depolarization in cancer cell lines along with the alterations in the metabolism of the cancer cells upon dosing with the vanadium complexes. Cancer cell invasion and growth are also found to be markedly reduced by peroxo complexes of vanadium. The studies included in the review paper have been taken from leading indexing databases and focus was laid on recent reports in literature. The biological potential of vanadium complexes of Schiff bases opens new horizons for future interdisciplinary studies and investigation focussed on understanding the biochemistry of these complexes, along with designing new complexes which have better bioavailability, solubility and low or non-toxicity.
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Affiliation(s)
- Kulsum Hashmi
- Department of Chemistry, Isabella Thoburn College, Lucknow, UP 226007, India
| | - Sakshi Gupta
- Department of Chemistry, Isabella Thoburn College, Lucknow, UP 226007, India
| | - Armeen Siddique
- Department of Chemistry, Isabella Thoburn College, Lucknow, UP 226007, India
| | - Tahmeena Khan
- Department of Chemistry, Integral University, Lucknow, UP 226026, India
| | - Seema Joshi
- Department of Chemistry, Isabella Thoburn College, Lucknow, UP 226007, India.
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2
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Miller SL, Gaidamauskas E, Altaf AA, Crans DC, Levinger NE. Where Are Sodium Ions in AOT Reverse Micelles? Fluoride Anion Probes Nanoconfined Ions by 19F Nuclear Magnetic Resonance Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37219990 DOI: 10.1021/acs.langmuir.3c00649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Confining water to nanosized spaces creates a unique environment that can change water's structural and dynamic properties. When ions are present in these nanoscopic spaces, the limited number of water molecules and short screening length can dramatically affect how ions are distributed compared to the homogeneous distribution assumed in bulk aqueous solution. Here, we demonstrate that the chemical shift observed in 19F NMR spectroscopy of fluoride anion, F-, probes the location of sodium ions, Na+, confined in reverse micelles prepared from AOT (sodium dioctyl sulfosuccinate) surfactants. Our measurements show that the nanoconfined environment of reverse micelles can lead to extremely high apparent ion concentrations and ionic strength, beyond the limit in bulk aqueous solutions. Most notably, the 19F NMR chemical shift trends we observe for F- in the reverse micelles indicate that the AOT sodium counterions remain at or near the interior interface between surfactant and water, thus providing the first experimental support for this hypothesis.
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Affiliation(s)
- Samantha L Miller
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Ernestas Gaidamauskas
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Ataf Ali Altaf
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
- Department of Chemistry, University of Okara, Okara 56300, Pakistan
| | - Debbie C Crans
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
- Cell and Molecular Biology Program, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Nancy E Levinger
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523, United States
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3
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The Journey of 1-Keto-1,2,3,4-Tetrahydrocarbazole Based Fluorophores: From Inception to Implementation. J Fluoresc 2022; 32:2023-2052. [PMID: 35829843 DOI: 10.1007/s10895-022-03004-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 07/01/2022] [Indexed: 10/17/2022]
Abstract
Carbazole is a unique template associated with several biological activities. It is due to the diverse and versatile biological properties of carbazole derivatives that they are of immense interest to the research community. 1-keto-1,2,3,4-tetrahydrocarbazoles are important synthetic intermediates to obtain carbazole derivatives. Several members of this family emit fluorescence on photoexcitation. In the context of biochemical and biophysical research, designing and characterising small molecule environment sensitive fluorophores is extremely significant. This article aims to be a state of the art review with synthetic and photophysical details of a variety of fluorophores based on 1-keto-1,2,3,4-tetrahydrocarbazole skeleton.
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4
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Adams EM, Hao H, Leven I, Rüttermann M, Wirtz H, Havenith M, Head‐Gordon T. Proton Traffic Jam: Effect of Nanoconfinement and Acid Concentration on Proton Hopping Mechanism. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ellen M. Adams
- Lehrstuhl für Physkalische Chemie II Ruhr Universität Bochum 44801 Bochum Germany
| | - Hongxia Hao
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley California 94720 USA
- Kenneth S. Pitzer Center for Theoretical Chemistry University of California Berkeley California 94720 USA
- Department of Chemistry University of California Berkeley California 94720 USA
| | - Itai Leven
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley California 94720 USA
- Kenneth S. Pitzer Center for Theoretical Chemistry University of California Berkeley California 94720 USA
- Department of Chemistry University of California Berkeley California 94720 USA
| | | | - Hanna Wirtz
- Lehrstuhl für Physkalische Chemie II Ruhr Universität Bochum 44801 Bochum Germany
| | - Martina Havenith
- Lehrstuhl für Physkalische Chemie II Ruhr Universität Bochum 44801 Bochum Germany
| | - Teresa Head‐Gordon
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley California 94720 USA
- Kenneth S. Pitzer Center for Theoretical Chemistry University of California Berkeley California 94720 USA
- Department of Chemistry University of California Berkeley California 94720 USA
- Department of Chemical and Biomolecular Engineering University of California Berkeley California 94720 USA
- Department of Bioengineering University of California Berkeley California 94720 USA
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5
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Havenith-Newen M, Adams EM, Head-Gordon T, Hao H, Rüttermann M, Leven I, Wirtz H. Proton Traffic Jam: Effect of Nanoconfinement and Acid Concentration on Proton Hopping Mechanism. Angew Chem Int Ed Engl 2021; 60:25419-25427. [PMID: 34402145 PMCID: PMC9293324 DOI: 10.1002/anie.202108766] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Indexed: 11/06/2022]
Abstract
The properties of the water network in concentrated HCl acid pools in nanometer-sized reverse non-ionic micelles were probed with TeraHertz absorption, dielectric relaxation spectroscopy, and reactive force field simulations capable of describing proton hopping mechanisms. We identify that only at a critical micelle size of W0=9 do solvated proton complexes form in the water pool, accompanied by a change in mechanism from Grotthuss forward shuttling to one that favors local oscillatory hopping. This is due to a preference for H+ and Cl- ions to adsorb to the micelle interface, together with an acid concentration effect that causes a "traffic jam" in which the short-circuiting of the hydrogen-bonding motif of the hydronium ion decreases the forward hopping rate throughout the water interior even as the micelle size increases. These findings have implications for atmospheric chemistry, biochemical and biophysical environments, and energy materials, as transport of protons vital to these processes can be suppressed due to confinement, aggregation, and/or concentration.
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Affiliation(s)
- Martina Havenith-Newen
- Ruhr-Universit�t Bochum, Physical Chemistry, Universit�tsstr. 150, 44780, Bochum, GERMANY
| | - Ellen M Adams
- Ruhr-Universität Bochum: Ruhr-Universitat Bochum, Chemistry and Biochemistry, GERMANY
| | - Teresa Head-Gordon
- UC Berkeley: University of California Berkeley, Chemistry, UNITED STATES
| | - Hongxia Hao
- Berkeley Laboratory: E O Lawrence Berkeley National Laboratory, Chemistry, UNITED STATES
| | | | - Itai Leven
- Lawrence Livermore National Laboratory, chemistry, GERMANY
| | - Hanna Wirtz
- Ruhr-Universität Bochum: Ruhr-Universitat Bochum, Chemistry, GERMANY
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6
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Wiebenga-Sanford BP, Washington JB, Cosgrove B, Palomares EF, Vasquez DA, Rithner CD, Levinger NE. Sweet Confinement: Glucose and Carbohydrate Osmolytes in Reverse Micelles. J Phys Chem B 2018; 122:9555-9566. [DOI: 10.1021/acs.jpcb.8b07406] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Jack B. Washington
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Brett Cosgrove
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Eduardo F. Palomares
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Derrick A. Vasquez
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Christopher D. Rithner
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Nancy E. Levinger
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
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7
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Sarkar Y, Majumder R, Das S, Ray A, Parui PP. Detection of Curvature-Radius-Dependent Interfacial pH/Polarity for Amphiphilic Self-Assemblies: Positive versus Negative Curvature. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:6271-6284. [PMID: 29268016 DOI: 10.1021/acs.langmuir.7b03888] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
It is possible that a defined curvature at the membrane interface controls its pH/polarity to exhibit specific bioactivity. By utilizing an interface-interacting spiro-rhodamine pH probe and the Schiff base polarity probe, we have shown that the pH deviation from the bulk phase to the interface (ΔpH)/interfacial dielectric constant (κ(i)) for amphiphilic self-assemblies can be regulated by the curvature geometry (positive/negative) and its radius. According to 1H NMR and fluorescence anisotropy investigations, the probes selectively interact with an anionic interfacial Stern layer. The ΔpH/κ(i) values for the Stern layer are estimated by UV-vis absorption and fluorescence studies. For the anionic sodium bis-2-ethylhexyl-sulfosuccinate (AOT) inverted micellar (IM) negative interface, the highly restricted water and proton penetration into the Stern layer owing to tight surfactant packing or a reduced water-exposed headgroup area may be responsible for the much lower ΔpH ≈ -0.45 and κ(i) ≈ 28 in comparison to ∼-2.35 and ∼44, respectively, for the anionic sodium dodecyl sulfate (SDS) micellar positive interface with a close similar Stern layer. With increasing AOT IM water-pool radius (1.7-9.5 nm) or [water]/[AOT] ratio ( w0) (8.0-43.0), the ΔpH and κ(i) increase maximally up to ∼-1.22 and ∼45, respectively, due to a greater water-exposed headgroup area. However, the unchanged ΔpH ≈ -0.65 and κ(i) ≈ 53.0 within radii ∼3.5-8.0 nm for the positive interface of a mixed Triton X-100 (TX-100)/SDS (4:1) micelle justify its packing flexibility. Interestingly, the continuously increasing ΔpH trend for IM up to its largest possible water-pool radius of ∼9.5 nm may rationalize the increase in ΔpH (∼-1.4 to -1.6) with the change in the curvature radii (∼15 to 50 nm) for sodium 1,2-dimyristoyl- sn-glycero-3-phosphorylglycerol (DMPG)/1,2-dimyristoyl- sn-glycero-3-phosphocholine (DMPC) (2:1) large unilamellar vesicles (LUV) owing to its negative interface. Whereas, similar to the micellar positive interface, the unchanged ΔpH at the positive LUV interface was confirmed by fluorescence microscopic studies with giant unilamellar vesicles of identical lipids composition. The present study offers a unique and simple method of monitoring the curvature-radius-dependent interfacial pH/polarity for biologically related membranes.
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Affiliation(s)
- Yeasmin Sarkar
- Department of Chemistry , Jadavpur University , Kolkata 700032 , India
| | - Rini Majumder
- Department of Chemistry , Jadavpur University , Kolkata 700032 , India
| | - Sanju Das
- Department of Chemistry , Jadavpur University , Kolkata 700032 , India
- Department of Chemistry , Maulana Azad College , Kolkata 700013 , India
| | - Ambarish Ray
- Department of Chemistry , Maulana Azad College , Kolkata 700013 , India
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8
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Sánchez-Lombardo I, Baruah B, Alvarez S, Werst KR, Segaline NA, Levinger NE, Crans DC. Size and shape trump charge in interactions of oxovanadates with self-assembled interfaces: application of continuous shape measure analysis to the decavanadate anion. NEW J CHEM 2016. [DOI: 10.1039/c5nj01788b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using 51V NMR spectroscopy, dynamic light scattering and continuous shape analysis to characterize two polyoxometalate-encapsulation in reverse micelles.
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Affiliation(s)
| | - Bharat Baruah
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
- Department of Chemistry
| | - Santiago Alvarez
- Departament de Química Inorganica
- Institut de Química Teorica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
| | - Katarina R. Werst
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
| | | | - Nancy E. Levinger
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
| | - Debbie C. Crans
- Department of Chemistry
- Colorado State University
- Colorado 80523-1872
- USA
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9
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Sostarecz AG, Gaidamauskas E, Distin S, Bonetti SJ, Levinger NE, Crans DC. Correlation of insulin-enhancing properties of vanadium-dipicolinate complexes in model membrane systems: phospholipid langmuir monolayers and AOT reverse micelles. Chemistry 2014; 20:5149-59. [PMID: 24615733 DOI: 10.1002/chem.201201803] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 07/07/2013] [Indexed: 11/10/2022]
Abstract
We explore the interactions of V(III) -, V(IV) -, and V(V) -2,6-pyridinedicarboxylic acid (dipic) complexes with model membrane systems and whether these interactions correlate with the blood-glucose-lowering effects of these compounds on STZ-induced diabetic rats. Two model systems, dipalmitoylphosphatidylcholine (DPPC) Langmuir monolayers and AOT (sodium bis(2-ethylhexyl)sulfosuccinate) reverse micelles present controlled environments for the systematic study of these vanadium complexes interacting with self-assembled lipids. Results from the Langmuir monolayer studies show that vanadium complexes in all three oxidation states interact with the DPPC monolayer; the V(III) -phospholipid interactions result in a slight decrease in DPPC molecular area, whereas V(IV) and V(V) -phospholipid interactions appear to increase the DPPC molecular area, an observation consistent with penetration into the interface of this complex. Investigations also examined the interactions of V(III) - and V(IV) -dipic complexes with polar interfaces in AOT reverse micelles. Electron paramagnetic resonance spectroscopic studies of V(IV) complexes in reverse micelles indicate that the neutral and smaller 1:1 V(IV) -dipic complex penetrates the interface, whereas the larger 1:2 V(IV) complex does not. UV/Vis spectroscopy studies of the anionic V(III) -dipic complex show only minor interactions. These results are in contrast to behavior of the V(V) -dipic complex, [VO2 (dipic)](-) , which penetrates the AOT/isooctane reverse micellar interface. These model membrane studies indicate that V(III) -, V(IV) -, and V(V) -dipic complexes interact with and penetrate the lipid interfaces differently, an effect that agrees with the compounds' efficacy at lowering elevated blood glucose levels in diabetic rats.
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Affiliation(s)
- Audra G Sostarecz
- Chemistry Department, Monmouth College, 700 E. Broadway, Monmouth, IL 61462 (USA)
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10
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Marques BS, Nucci NV, Dodevski I, Wang KWC, Athanasoula EA, Jorge C, Wand AJ. Measurement and control of pH in the aqueous interior of reverse micelles. J Phys Chem B 2014; 118:2020-31. [PMID: 24506449 PMCID: PMC3983379 DOI: 10.1021/jp4103349] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
![]()
The
encapsulation of proteins and nucleic acids within the nanoscale
water core of reverse micelles has been used for over 3 decades as
a vehicle for a wide range of investigations including enzymology,
the physical chemistry of confined spaces, protein and nucleic acid
structural biology, and drug development and delivery. Unfortunately,
the static and dynamical aspects of the distribution of water in solutions
of reverse micelles complicate the measurement and interpretation
of fundamental parameters such as pH. This is a severe disadvantage
in the context of (bio)chemical reactions and protein structure and
function, which are generally highly sensitive to pH. There is a need
to more fully characterize and control the effective pH of the reverse
micelle water core. The buffering effect of titratable head groups
of the reverse micelle surfactants is found to often be the dominant
variable defining the pH of the water core. Methods for measuring
the pH of the reverse micelle aqueous interior using one-dimensional 1H and two-dimensional heteronuclear NMR spectroscopy are described.
Strategies for setting the effective pH of the reverse micelle water
core are demonstrated. The exquisite sensitivity of encapsulated proteins
to the surfactant, water content, and pH of the reverse micelle is
also addressed. These results highlight the importance of assessing
the structural fidelity of the encapsulated protein using multidimensional
NMR before embarking upon a detailed structural and biophysical characterization.
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Affiliation(s)
- Bryan S Marques
- Graduate Group in Biochemistry and Molecular Biophysics and Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine , Philadelphia, Pennsylvania 19104-6059, United States
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11
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Kittipongpittaya K, Panya A, McClements DJ, Decker EA. Impact of Free Fatty Acids and Phospholipids on Reverse Micelles Formation and Lipid Oxidation in Bulk Oil. J AM OIL CHEM SOC 2013. [DOI: 10.1007/s11746-013-2388-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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12
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Differentiating impact of the AOT-stabilized droplets of water-in-octane microemulsions as examined using halogenated fluoresceins as molecular probes. J Mol Liq 2013. [DOI: 10.1016/j.molliq.2013.08.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Crans DC, Woll KA, Prusinskas K, Johnson MD, Norkus E. Metal speciation in health and medicine represented by iron and vanadium. Inorg Chem 2013; 52:12262-75. [PMID: 24041403 DOI: 10.1021/ic4007873] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The influence of metals in biology has become more and more apparent within the past century. Metal ions perform essential roles as critical scaffolds for structure and as catalysts in reactions. Speciation is a key concept that assists researchers in investigating processes that involve metal ions. However, translation of the essential area across scientific fields has been plagued by language discrepancies. To rectify this, the IUPAC Commission provided a framework in which speciation is defined as the distribution of species. Despite these attempts, contributions from inorganic chemists to the area of speciation have not fully materialized in part because the past decade's contributions focused on technological advances, which are not yet to the stage of measuring speciation distribution in biological solutions. In the following, we describe how speciation influences the area of metals in medicine and how speciation distribution has been characterized so far. We provide two case studies as an illustration, namely, vanadium and iron. Vanadium both has therapeutic importance and is known as a cofactor for metalloenzymes. In addition to being a cation, vanadium(V) has analogy with phosphorus and as such is a potent inhibitor for phosphorylases. Because speciation can change the metal's existence in cationic or anionic forms, speciation has profound effects on biological systems. We also highlight how speciation impacts iron metabolism, focusing on the rather low abundance of biologically relevant iron cation that actually exists in biological fluids. fluids. Furthermore, we point to recent investigations into the mechanism of Fenton chemistry, and that the emerging results show pH dependence. The studies suggest formation of Fe(IV)-intermediates and that the generally accepted mechanism may only apply at low pH. With broader recognition toward biological speciation, we are confident that future investigations on metal-based systems will progress faster and with significant results. Studying metal complexes to explore the properties of a potential "active species" and further uncovering the details associated with their specific composition and geometry are likely to be important to the action.
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Affiliation(s)
- Debbie C Crans
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States
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14
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McCann N, Wagner M, Hasse H. A thermodynamic model for vanadate in aqueous solution--equilibria and reaction enthalpies. Dalton Trans 2012; 42:2622-8. [PMID: 23223605 DOI: 10.1039/c2dt31993d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Nichola McCann
- Laboratory of Engineering Thermodynamics, Department of Mechanical and Process Engineering, University of Kaiserslautern, Erwin-Schrödinger-Straße 44, 67663 Kaiserslautern, Germany.
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15
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Crans DC, Levinger NE. The conundrum of pH in water nanodroplets: sensing pH in reverse micelle water pools. Acc Chem Res 2012; 45:1637-45. [PMID: 22812536 DOI: 10.1021/ar200269g] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In aqueous environments, acidity is arguably the most important property dictating the chemical, physical, and biological processes that can occur. However, in a variety of environments where the minuscule size limits the number of water molecules, the conventional macroscopic description of pH is no longer valid. This situation arises for any and all nanoscopically confined water including cavities in minerals, porous solids, zeolites, atmospheric aerosols, enzyme active sites, membrane channels, and biological cells and organelles. To understand pH in these confined spaces, we have explored reverse micelles as a model system that confines water to nanoscale droplets. At the appropriate concentrations, reverse micelles form in ternary or higher order solutions of nonpolar solvent, polar solvent (usually water), and amphipathic molecules, usually surfactants or lipids. Measuring the acidity, or local density of protons, commonly known as pH, of these nanoscopic water pools in reverse micelles is challenging. First, because the volume of the water in these reverse micelles is so minute, we cannot probe its proton concentration using traditional pH meters. Second, the traditional concept of pH breaks down in a nanosystem that includes fewer than 10(7) water molecules. Third, the interpretation of results from studies attempting to measure acidity or pH in these environments is nontrivial because the conditions fall outside the accepted IUPAC definition for pH. Researchers have developed experimental methods to measure acidity indirectly using various spectroscopic probe molecules. Most measurements of intramicellar pH have employed optical spectroscopy of organic probe molecules containing at least one labile proton coupled to electronic transitions to track pH changes in the environment. These indirect measurements of the pH reflect the local environment sensed by the probe and are complicated by the probe location within the sample and how that location affects properties such as pK(a). Thus, interpretation of the measurement in the highly heterogeneous reverse micellar environment can be challenging. Organic pH probes can often produce ambiguous acidity measurements, because the probes can readily associate with or penetrate the micellar interface. Protonation can also dramatically change the polarity of the probe and shift the probe's location within the system. As a result, researchers have developed highly charged pH-sensitive probes such as hydroxypyrene trisulfonate, vanadate or phosphate that reside in the water pool both before and after protonation. For inorganic probes researchers have used multinuclear NMR spectroscopy to directly measure conditions in the water droplet. Regardless of the probe and method employed, reverse micellar studies include many implicit assumptions. All reported pH measurements comprise averages of molecular ensembles rather than the response of a single molecule. Experiments also represent averages of the dynamic reverse micelles over the time of the experiments. Thus the experiments report results from an average molecular position, pK(a), ionic strength, viscosity, etc. Although the exact meaning of pH in nanosized waterpools challenges scientific intuition and experimental data are non-trivial to interpret, continued experimental studies are critical to improve understanding of these nanoscopic water pools. Experimental data will allow theorists the tools to develop the models that further explore the meaning of pH in nanosized environments.
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Affiliation(s)
- Debbie C. Crans
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Nancy E. Levinger
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
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16
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Méndez-Pérez M, García-Río L, Pérez-Lorenzo M. Boosting Lewis Acid Catalysis in Water-in-Oil Metallomicroemulsions. ChemCatChem 2012. [DOI: 10.1002/cctc.201200337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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McPhee JT, Scott E, Levinger NE, Van Orden A. Cy3 in AOT Reverse Micelles I. Dimer Formation Revealed through Steady-State and Time-Resolved Spectroscopy. J Phys Chem B 2011; 115:9576-84. [DOI: 10.1021/jp200126f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Jeffrey T. McPhee
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Eric Scott
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Nancy E. Levinger
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Alan Van Orden
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
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18
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McPhee JT, Scott E, Levinger NE, Van Orden A. Cy3 in AOT Reverse Micelles II. Probing Intermicellar Interactions Using Fluorescence Correlation Spectroscopy. J Phys Chem B 2011; 115:9585-92. [DOI: 10.1021/jp2001282] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jeffrey T McPhee
- Colorado State University, Department of Chemistry, Fort Collins, Colorado 80523, USA
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Falcone RD, Baruah B, Gaidamauskas E, Rithner CD, Correa NM, Silber JJ, Crans DC, Levinger NE. Layered Structure of Room-Temperature Ionic Liquids in Microemulsions by Multinuclear NMR Spectroscopic Studies. Chemistry 2011; 17:6837-46. [DOI: 10.1002/chem.201002182] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 01/26/2011] [Indexed: 11/09/2022]
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20
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Levinger NE, Rubenstrunk LC, Baruah B, Crans DC. Acidification of reverse micellar nanodroplets by atmospheric pressure CO2. J Am Chem Soc 2011; 133:7205-14. [PMID: 21506532 DOI: 10.1021/ja2011737] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Water absorption of atmospheric carbon dioxide lowers the solution pH due to carbonic acid formation. Bulk water acidification by CO(2) is well documented, but significantly less is known about its effect on water in confined spaces. Considering its prominence as a greenhouse gas, the importance of aerosols in acid rain, and CO(2)-buffering in cellular systems, surprisingly little information exists about the absorption of CO(2) by nanosized water droplets. The fundamental interactions of CO(2) with water, particularly in nanosized structures, may influence a wide range of processes in our technological society. Here results from experiments investigating the uptake of gaseous CO(2) by water pools in reverse micelles are presented. Despite the small number of water molecules in each droplet, changes in vanadium probes within the water pools, measured using vanadium-51 NMR spectroscopy, indicate a significant drop in pH after CO(2) introduction. Collectively, the pH-dependent vanadium probes show CO(2) dissolves in the nanowater droplets, causing the reverse micelle acidity to increase.
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Affiliation(s)
- Nancy E Levinger
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA.
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21
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Binks DA, Spencer N, Wilkie J, Britton MM. Magnetic Resonance Studies of a Redox Probe in a Reverse Sodium Bis(2-ethylhexyl)sulfosuccinate/Octane/Water Microemulsion. J Phys Chem B 2010; 114:12558-64. [DOI: 10.1021/jp106709m] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel A. Binks
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT
| | - Neil Spencer
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT
| | - John Wilkie
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT
| | - Melanie M. Britton
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT
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22
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Satpati AK, Kumbhakar M, Nath S, Pal H. Influence of Confined Water on the Photophysics of Dissolved Solutes in Reverse Micelles. Chemphyschem 2009; 10:2966-78. [DOI: 10.1002/cphc.200900527] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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23
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Crans DC, Baruah B, Ross A, Levinger NE. Impact of confinement and interfaces on coordination chemistry: Using oxovanadate reactions and proton transfer reactions as probes in reverse micelles. Coord Chem Rev 2009. [DOI: 10.1016/j.ccr.2009.01.031] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Sedgwick MA, Crans DC, Levinger NE. What is inside a nonionic reverse micelle? Probing the interior of Igepal reverse micelles using decavanadate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:5496-5503. [PMID: 19388632 DOI: 10.1021/la8035067] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The interiors of reverse micelles formed using nonionic surfactants to sequester water droplets in a nonpolar environment have been investigated using the decavanadate molecule as a probe. Chemical shifts and line widths of the three characteristic signals in the 51V NMR spectrum of decavanadate, corresponding to vanadium atoms in equatorial peripheral, equatorial interior, and axial locations, measure the local proton concentration and characteristics of the reverse micellar interior near the decavandate probe. All samples investigated indicate deprotonation of the vanadate probe in the reverse micelle environment. However, the relative mobility of the decavanadate molecule depends on the reverse micellar components. Specifically, the 51V NMR signals of the decavandate in reverse micelles formed using only the Igepal CO-520 surfactant display sharp signals indicating that the decavandate molecule tumbles relatively freely while reverse micelles formed from a mixture of Igepal CO-610 and -430 present a more viscous environment for the decavanadate molecule; the nature of the interior of the nonionic reverse water pool varies significantly depending on the specific Igepal. The 51V NMR spectra also indicate that the interior core water pool of the reverse micelles is less acidic than the bulk aqueous solution from which the samples were created. Together, these data provide a description that allows for a comparison of the water pools in these different nonionic reverse micelles.
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Affiliation(s)
- M A Sedgwick
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
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25
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Aureliano M, Crans DC. Decavanadate (V10 O28 6-) and oxovanadates: oxometalates with many biological activities. J Inorg Biochem 2009; 103:536-46. [PMID: 19110314 DOI: 10.1016/j.jinorgbio.2008.11.010] [Citation(s) in RCA: 190] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2008] [Revised: 11/10/2008] [Accepted: 11/18/2008] [Indexed: 02/07/2023]
Abstract
The decameric vanadate species V(10)O(28)(6-), also referred to as decavanadate, impact proteins, lipid structures and cellular function, and show some effects in vivo on oxidative stress processes and other biological properties. The mode of action of decavanadate in many biochemical systems depends, at least in part, on the charge and size of the species and in some cases competes with the simpler oxovanadate species. The orange decavanadate that contains 10 vanadium atoms is a stable species for several days at neutral pH, but at higher pH immediately converts to the structurally and functionally distinct lower oxovanadates such as the monomer, dimer or tetramer. Although the biological effects of vanadium are generally assumed to derive from monomeric vanadate or the vanadyl cation, we show in this review that not all effects can be attributed to these simple oxovanadate forms. This topic has not previously been reviewed although background information is available [D.C. Crans, Comments Inorg. Chem. 16 (1994) 35-76; M. Aureliano (Ed.), Vanadium Biochemistry, Research Signpost Publs., Kerala, India, 2007]. In addition to pumps, channels and metabotropic receptors, lipid structures represent potential biological targets for decavanadate and some examples have been reported. Decavanadate interact with enzymes, polyphosphate, nucleotide and inositol 3-phosphate binding sites in the substrate domain or in an allosteric site, in a complex manner. In mitochondria, where vanadium was shown to accumulate following decavanadate in vivo administration, nM concentration of decavanadate induces membrane depolarization in addition to inhibiting oxygen consumption, suggesting that mitochondria may be potential targets for decameric toxicity. In vivo effects of decavanadate in piscine models demonstrated that antioxidant stress markers, lipid peroxidation and vanadium subcellular distribution is dependent upon whether or not the solutions administered contain decavanadate. The present review summarizes the reports on biological effects of decavanadate and highlights the importance of considering decavanadate in evaluations of the biological effects of vanadium.
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Affiliation(s)
- Manuel Aureliano
- CCMar and Dept. Chemistry, Biochemistry and Pharmacy, FCT, University of Algarve, Faro, Portugal.
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26
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Nikolakis VA, Tsalavoutis JT, Stylianou M, Evgeniou E, Jakusch T, Melman A, Sigalas MP, Kiss T, Keramidas AD, Kabanos TA. Vanadium(V) Compounds with the Bis-(hydroxylamino)-1,3,5-triazine Ligand, H2bihyat: Synthetic, Structural, and Physical Studies of [V2VO3(bihyat)2] and of the Enhanced Hydrolytic Stability Species cis-[VVO2(bihyat)]−. Inorg Chem 2008; 47:11698-710. [DOI: 10.1021/ic801411x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Vladimiros A. Nikolakis
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - John T. Tsalavoutis
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Marios Stylianou
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Evgenios Evgeniou
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Tamas Jakusch
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Artem Melman
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Michael P. Sigalas
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Tamas Kiss
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Anastasios D. Keramidas
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
| | - Themistoklis A. Kabanos
- Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, Ioannina 45110, Greece, Department of Chemistry, Laboratory of Applied Quantum Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece, Department of Chemistry, University of Cyprus, Nicosia 1678, Cyprus, Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, New York 13699, and Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary
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Baruah B, Swafford LA, Crans DC, Levinger NE. Do Probe Molecules Influence Water in Confinement? J Phys Chem B 2008; 112:10158-64. [DOI: 10.1021/jp800390t] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Bharat Baruah
- Department of Chemistry, Colorado State University, Colorado 80523-1872
| | - Laura A. Swafford
- Department of Chemistry, Colorado State University, Colorado 80523-1872
| | - Debbie C. Crans
- Department of Chemistry, Colorado State University, Colorado 80523-1872
| | - Nancy E. Levinger
- Department of Chemistry, Colorado State University, Colorado 80523-1872
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Owrutsky JC, Pomfret MB, Barton DJ, Kidwell DA. Fourier transform infrared spectroscopy of azide and cyanate ion pairs in AOT reverse micelles. J Chem Phys 2008; 129:024513. [DOI: 10.1063/1.2952522] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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29
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Li M, Ding W, Baruah B, Crans DC, Wang R. Inhibition of protein tyrosine phosphatase 1B and alkaline phosphatase by bis(maltolato)oxovanadium (IV). J Inorg Biochem 2008; 102:1846-53. [PMID: 18728000 DOI: 10.1016/j.jinorgbio.2008.06.007] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 06/01/2008] [Accepted: 06/05/2008] [Indexed: 11/25/2022]
Abstract
Vanadate has been recognized as a specific and potent phosphatase inhibitor since its structure is similar to that of phosphate. In this study, we measured the inhibition of glutathione S-transferase-tagged protein tyrosine phosphatase 1B (GST-PTP1B) and alkaline phosphatase (ALP) by the insulin enhancing compounds, bis(maltolato)oxovanadium(IV) (BMOV). The results showed that the activity of GST-PTP1B was reversibly inhibited by solutions of BMOV with an IC(50) value of 0.86+/-0.02 microM. Steady state kinetic studies showed that inhibition of GST-PTP1B by BMOV was of a mixed competitive and noncompetitive type. In addition, incubation of GST-PTP1B with BMOV showed a time-dependent biphasic inactivation of the protein. On the other hand, the inhibitory behavior of BMOV on ALP activity was reversible and competitive with an IC(50) value of 32.1+/-0.6 microM. Incubation with BMOV did not show biphasic inactivation of ALP. The reversible inhibition of GST-PTP1B by BMOV is more potent than that of ALP, but solutions of BMOV inhibited both enzymes. This data support the suggestion that mechanisms for the inhibitory effects of BMOV on GST-PTP1B and ALP are very different.
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Affiliation(s)
- Ming Li
- College of Life Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049, China
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Impairment of ascorbic acid’s anti-oxidant properties in confined media: Inter and intramolecular reactions with air and vanadate at acidic pH. J Inorg Biochem 2008; 102:1334-47. [DOI: 10.1016/j.jinorgbio.2008.01.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Revised: 01/04/2008] [Accepted: 01/10/2008] [Indexed: 11/22/2022]
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