1
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Yoshinari N, Kuwamura N, Kojima T, Konno T. Development of coordination chemistry with thiol-containing amino acids. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214857] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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2
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Liu G, Li Y, Lu Y, Jia Y, Shan J, Liu Q. Label-Free Sensing of Cysteine through Cadmium Ion Coordination: Smartphone-Based Electrochemical Detection. Chempluschem 2022; 87:e202200040. [PMID: 35319831 DOI: 10.1002/cplu.202200040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/07/2022] [Indexed: 11/09/2022]
Abstract
The detection of biologically important compounds such as cysteine remains a challenge for monitoring body metabolism. This work proposes a transition metal ion coordination-based label-free cysteine sensor with smartphone-based square wave voltammetry sensing system for the point-of-care testing (POCT). In the sensing system, potential excitation and current measurements were accomplished by a miniaturized and integrated circuit board with a smartphone to wirelessly control the system via Bluetooth. The electrochemical currents changed with the cysteine concentrations ranging from 0 μM to 200 μM with a linearity correlation coefficient of 0.9915. The limit of detection was as low as 0.0149 μM for cysteine. The smartphone-based system provides an effective strategy for cysteine detection, and it can also serve as a promising portable sensing platform for the analysis of other small molecules.
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Affiliation(s)
- Guang Liu
- Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Yaru Li
- Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Yanli Lu
- Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Yixuan Jia
- Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Jianzhen Shan
- Department of Medical oncology, The First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310003, P. R. China
| | - Qingjun Liu
- Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
- Department of Medical oncology, The First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310003, P. R. China
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3
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Fromsejer R, Mikkelsen KV, Hemmingsen L. Dynamics of nuclear recoil: QM-BOMD simulations of model systems following β-decay. Phys Chem Chem Phys 2021; 23:25689-25698. [PMID: 34755727 DOI: 10.1039/d1cp02112e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The kinetic recoil energy received by the daughter nucleus in a nuclear decay is often large enough to affect the structure around the nucleus in chemical systems. The coinciding element change which typically occurs in a nuclear decay may additionally incur a structural reorganization. The effects of these phenomena on chemical systems where radio-isotopes are used are often little-known or neglected because the dynamics of nuclear decay is difficult to observe experimentally. In this work, QM-MD simulations are used to investigate local fs to ps dynamics following the β-decay of 111Ag to 111Cd in systems modelled on the metal-sensing CueR protein. An adiabatic approximation is applied, assuming that the electronic structure relaxes rapidly after the decay. PM7-MD simulations of recoil dynamics of the model systems show significant structural changes and bonding interactions that depend on the magnitude and direction of the recoil. We find that, in general, the kinetic recoil energy is rapidly distributed (<5 ps) uniformly throughout the systems in the studied scenarios.
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Affiliation(s)
- Rasmus Fromsejer
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
| | - Kurt V Mikkelsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
| | - Lars Hemmingsen
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 København Ø, Denmark.
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4
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Yin Z, Qiu D, Zhang M. Molecular level study of cadmium adsorption on dithiocarbamate modified chitosan. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 271:116322. [PMID: 33383420 DOI: 10.1016/j.envpol.2020.116322] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 12/09/2020] [Accepted: 12/13/2020] [Indexed: 06/12/2023]
Abstract
It has been shown that chemical modification of chitosan with sulfur (S) functional groups could significantly enhance its chelating capability with heavy metals included Cd(II). However, a molecular level understanding has been lacking. Here, we carried out X-ray absorption fine structure (XAFS) and Fourier transformed infrared (FTIR) spectra studies to bridge this knowledge gap. The results indicate that both Cd-O/N and Cd-S bonds exist in the complex of Cd(II) with dithiocarbamate chitosan (DTC-CTS). S functional groups (dithiocarbamate) in DTC-CTS play the major role in complexation with Cd(II) and S content affects the adsorption mechanism. At low S content, Cd(II) is mainly adsorbed on DTC-CTS as an outer-sphere complex with two monodentate amino groups and two water molecules in tetrahedral configuration. At high S content, Cd adsorption dominantly occurs by formation of an inner-sphere complex with two bidentate mononuclear S ligands in tetrahedral configuration. This investigation provides information on the effectiveness and mechanisms of Cd(II) removal that is critical for evaluating modified chitosan applications for stabilization of Cd(II) in surface water, groundwater, soils and sediments.
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Affiliation(s)
- Zheng Yin
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Dong Qiu
- Beijing National Laboratory for Molecule Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Meiyi Zhang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
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5
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Singh A, Yumnam S, Kunwar A, Tripathi VS, Neogy S, Rath MC. One‐Pot, Rapid and Facile Synthesis of Thioglycolic Acid capped CdSe quantum dots: Tuning of Properties, Mechanistic Investigations by Cyclic Voltammetry and Cytotoxicity Studies. ChemistrySelect 2020. [DOI: 10.1002/slct.202000974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Avinash Singh
- Department of Science & HumanitiesMLR Institute of Technology Dundigal Hyderabad India 500043
| | - Sujata Yumnam
- Department of Science & HumanitiesMLR Institute of Technology Dundigal Hyderabad India 500043
| | - Amit Kunwar
- Radiation and Photochemistry DivisionBhabha Atomic Research Centre Mumbai India 400085
| | - V. S. Tripathi
- Radiation and Photochemistry DivisionBhabha Atomic Research Centre Mumbai India 400085
| | - Suman Neogy
- Materials Science DivisionBhabha Atomic Research Centre Mumbai India 400085
| | - M. C. Rath
- Radiation and Photochemistry DivisionBhabha Atomic Research Centre Mumbai India 400085
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6
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Li J, Zhang L. 3D pothole-rich hierarchical carbon framework-encapsulated Ni nanoparticles for highly selective nonenzymatic cysteine detection. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.135126] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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7
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Mao X, Wang Z, Zeng D, Cao H, Zhan Y, Wang Y, Li Q, Shen Y, Wang J. Self-Assembled Chiral Nanoparticle Superstructures and Identification of Their Collective Optical Activity from Ligand Asymmetry. ACS NANO 2019; 13:2879-2887. [PMID: 30848884 DOI: 10.1021/acsnano.8b06269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The spontaneous self-assembly of chiral nanoparticles (NPs) into stationary fabrication has garnered great interest in technique investigation and science advancement due to its expected apparent properties via orderly collective behaviors. However, this kind of characterization of assembled nanoparticles superstructure (NPS) is rarely reported and is distinguished with monodispersed chiral NPs. In this work, we used l-cysteine (Cys) as the chiral molecule in the form of functional surfactant, which had capped CdS/CdTe NPs and was treated as a linkage bridge for constructing orderly assembled NPS. Among the circular dichrosim (CD) phenomenon, Cys ligands exhibit related changes in CD absorption, while whole-molecule solution was used for treatment in different pH-controlling procedures. Synthesized chiral NPs are organized into ordered rod-shaped NPS during the spontaneous self-assembly process, and the CD response of NPS is monitored in different cultivating times; it showed a persuasive response appears in sum frequency generation (SFG) spectroscopy. Both experimental works and theory calculation convey that the ordered stacking of chiral stabilizer and the chirality of NPS, which are identified from chiral molecular status and their collective optical activity, originated from ligand asymmetry.
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Affiliation(s)
- Xiang Mao
- State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and MOST, College of Biomedical Engineering , Chongqing Medical University , Chongqing 400016 , PR China
| | - Zhenyu Wang
- State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and MOST, College of Biomedical Engineering , Chongqing Medical University , Chongqing 400016 , PR China
| | - Deping Zeng
- State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and MOST, College of Biomedical Engineering , Chongqing Medical University , Chongqing 400016 , PR China
| | - Hua Cao
- State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and MOST, College of Biomedical Engineering , Chongqing Medical University , Chongqing 400016 , PR China
| | - Yang Zhan
- Department of Colorectal Cancer , Tianjin Medical University, Cancer Institute and Hospital (National Clinical Research Center for Cancer), Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer , Tianjin 300072 , PR China
| | | | | | | | - Jiefu Wang
- Department of Colorectal Cancer , Tianjin Medical University, Cancer Institute and Hospital (National Clinical Research Center for Cancer), Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer , Tianjin 300072 , PR China
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8
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Kurihara T, Noda Y, Takegoshi K. Capping Structure of Ligand-Cysteine on CdSe Magic-Sized Clusters. ACS OMEGA 2019; 4:3476-3483. [PMID: 31459562 PMCID: PMC6648626 DOI: 10.1021/acsomega.8b02752] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 01/29/2019] [Indexed: 05/31/2023]
Abstract
Ligand molecules capping on clusters largely affect the formation and stabilization mechanism and the property of clusters. In semiconductor CdSe clusters, cysteine is used as one of the ligands and allows the formation of ultrastable (CdSe)34 magic-sized clusters. Cysteine has sulfhydryl, amine, and carboxylate groups, all of which have coordination ability to the CdSe surface, and the bonding states of the three functional groups of ligand-cysteine on the CdSe core have not been determined. In this work, the capping structure of ligand-cysteine is examined by performing Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and multinuclear solid-state nuclear magnetic resonance (NMR) spectroscopy. FT-IR, XPS, and 1H, 13C, and 23Na magic-angle spinning NMR show that the sulfhydryl group of ligand-cysteine forms a sulfur-cadmium bond with a cadmium atom at the CdSe surface, while the carboxylate group does not contribute to the protection of the CdSe core and binds to a sodium ion contained as a counterion. 15N-{77Se} through-bond J-single quantum filtered NMR experiment reveals that the amine group of ligand-cysteine has no coordination to selenium atoms. By considering the N-Cd bond forming ratio (∼43%) revealed in our previous work, which is confirmed in this work by analyzing 13Cα signal intensity (∼42%), we concluded that cysteine capping on (CdSe)34 occurs in two ways: one involves both the sulfur-cadmium and nitrogen-cadmium bonds, and the other bears only the sulfur-cadmium bond.
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Affiliation(s)
- Takuya Kurihara
- Division
of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho,
Sakyo-ku, Kyoto 606-8502, Japan
| | - Yasuto Noda
- Division
of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho,
Sakyo-ku, Kyoto 606-8502, Japan
| | - Kiyonori Takegoshi
- Division
of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho,
Sakyo-ku, Kyoto 606-8502, Japan
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9
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Jung KH, Oh S, Park J, Park YJ, Park SH, Lee KH. A novel fluorescent peptidyl probe for highly sensitive and selective ratiometric detection of Cd(ii) in aqueous and bio-samplesviametal ion-mediated self-assembly. NEW J CHEM 2018. [DOI: 10.1039/c8nj02298d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A fluorescent peptidyl probe based on a Cd(ii)-triggered self-assembling process was proposed for ratiometric detection for Cd(ii) in urine and live cells.
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Affiliation(s)
- Kwan Ho Jung
- Bioorganic Chemistry Laboratory
- Center for Design and Applications of Molecular Catalysts
- Department of Chemistry and Chemical Engineering
- Inha University
- 253 Yonghyun-dong
| | - Semin Oh
- Bioorganic Chemistry Laboratory
- Center for Design and Applications of Molecular Catalysts
- Department of Chemistry and Chemical Engineering
- Inha University
- 253 Yonghyun-dong
| | - Joohee Park
- Bioorganic Chemistry Laboratory
- Center for Design and Applications of Molecular Catalysts
- Department of Chemistry and Chemical Engineering
- Inha University
- 253 Yonghyun-dong
| | - Yu Jin Park
- Bioorganic Chemistry Laboratory
- Center for Design and Applications of Molecular Catalysts
- Department of Chemistry and Chemical Engineering
- Inha University
- 253 Yonghyun-dong
| | - See-Hyoung Park
- Department of Bio and Chemical Engineering
- Hongik University
- Sejong 30016
- Republic of Korea
| | - Keun-Hyeung Lee
- Bioorganic Chemistry Laboratory
- Center for Design and Applications of Molecular Catalysts
- Department of Chemistry and Chemical Engineering
- Inha University
- 253 Yonghyun-dong
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10
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Bargiello TA, Oh S, Tang Q, Bargiello NK, Dowd TL, Kwon T. Gating of Connexin Channels by transjunctional-voltage: Conformations and models of open and closed states. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:22-39. [PMID: 28476631 DOI: 10.1016/j.bbamem.2017.04.028] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 11/18/2022]
Abstract
Voltage is an important physiologic regulator of channels formed by the connexin gene family. Connexins are unique among ion channels in that both plasma membrane inserted hemichannels (undocked hemichannels) and intercellular channels (aggregates of which form gap junctions) have important physiological roles. The hemichannel is the fundamental unit of gap junction voltage-gating. Each hemichannel displays two distinct voltage-gating mechanisms that are primarily sensitive to a voltage gradient formed along the length of the channel pore (the transjunctional voltage) rather than sensitivity to the absolute membrane potential (Vm or Vi-o). These transjunctional voltage dependent processes have been termed Vj- or fast-gating and loop- or slow-gating. Understanding the mechanism of voltage-gating, defined as the sequence of voltage-driven transitions that connect open and closed states, first and foremost requires atomic resolution models of the end states. Although ion channels formed by connexins were among the first to be characterized structurally by electron microscopy and x-ray diffraction in the early 1980's, subsequent progress has been slow. Much of the current understanding of the structure-function relations of connexin channels is based on two crystal structures of Cx26 gap junction channels. Refinement of crystal structure by all-atom molecular dynamics and incorporation of charge changing protein modifications has resulted in an atomic model of the open state that arguably corresponds to the physiologic open state. Obtaining validated atomic models of voltage-dependent closed states is more challenging, as there are currently no methods to solve protein structure while a stable voltage gradient is applied across the length of an oriented channel. It is widely believed that the best approach to solve the atomic structure of a voltage-gated closed ion channel is to apply different but complementary experimental and computational methods and to use the resulting information to derive a consensus atomic structure that is then subjected to rigorous validation. In this paper, we summarize our efforts to obtain and validate atomic models of the open and voltage-driven closed states of undocked connexin hemichannels. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
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Affiliation(s)
- Thaddeus A Bargiello
- Dominic P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States.
| | - Seunghoon Oh
- Department of Physiology, College of Medicine, Dankook University, Cheonan, Republic of Korea
| | - Qingxiu Tang
- Dominic P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Nicholas K Bargiello
- Dominic P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Terry L Dowd
- Department of Chemistry, Brooklyn College, Brooklyn, NY 11210, United States
| | - Taekyung Kwon
- Dominic P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States
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11
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Jabłońska A, Bender J, Gudat D, Ponikiewski Ł, Dołęga A. Comparison of the coordination geometries of Zn(II) and Cd(II) ions in complexes with water, methanol and bulky aryloxysilanethiolate ligands. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.05.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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12
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Linsdell P. Metal bridges to probe membrane ion channel structure and function. Biomol Concepts 2016; 6:191-203. [PMID: 26103632 DOI: 10.1515/bmc-2015-0013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 05/29/2015] [Indexed: 11/15/2022] Open
Abstract
Ion channels are integral membrane proteins that undergo important conformational changes as they open and close to control transmembrane flux of different ions. The molecular underpinnings of these dynamic conformational rearrangements are difficult to ascertain using current structural methods. Several functional approaches have been used to understand two- and three-dimensional dynamic structures of ion channels, based on the reactivity of the cysteine side-chain. Two-dimensional structural rearrangements, such as changes in the accessibility of different parts of the channel protein to the bulk solution on either side of the membrane, are used to define movements within the permeation pathway, such as those that open and close ion channel gates. Three-dimensional rearrangements – in which two different parts of the channel protein change their proximity during conformational changes – are probed by cross-linking or bridging together two cysteine side-chains. Particularly useful in this regard are so-called metal bridges formed when two or more cysteine side-chains form a high-affinity binding site for metal ions such as Cd2+ or Zn2+. This review describes the use of these different techniques for the study of ion channel dynamic structure and function, including a comprehensive review of the different kinds of conformational rearrangements that have been studied in different channel types via the identification of intra-molecular metal bridges. Factors that influence the affinities and conformational sensitivities of these metal bridges, as well as the kinds of structural inferences that can be drawn from these studies, are also discussed.
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13
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da Silva CR, Almeida GS, Caldeira-de-Araújo A, Leitão AC, de Pádula M. Influence of Ogg1 repair on the genetic stability of ccc2 mutant of Saccharomyces cerevisiae chemically challenged with 4-nitroquinoline-1-oxide (4-NQO). Mutagenesis 2015; 31:107-14. [PMID: 26275420 DOI: 10.1093/mutage/gev062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In Saccharomyces cerevisiae, disruption of genes by deletion allowed elucidation of the molecular mechanisms of a series of human diseases, such as in Wilson disease (WD). WD is a disorder of copper metabolism, due to inherited mutations in human copper-transporting ATPase (ATP7B). An orthologous gene is present in S. cerevisiae, CCC2 gene. Copper is required as a cofactor for a number of enzymes. In excess, however, it is toxic, potentially carcinogenic, leading to many pathological conditions via oxidatively generated DNA damage. Deficiency in ATP7B (human) or Ccc2 (yeast) causes accumulation of intracellular copper, favouring the generation of reactive oxygen species. Thus, it becomes important to study the relative importance of proteins involved in the repair of these lesions, such as Ogg1. Herein, we addressed the influence Ogg1 repair in a ccc2 deficient strain of S. cerevisiae. We constructed ccc2-disrupted strains from S. cerevisiae (ogg1ccc2 and ccc2), which were analysed in terms of viability and spontaneous mutator phenotype. We also investigated the impact of 4-nitroquinoline-1-oxide (4-NQO) on nuclear DNA damage and on the stability of mitochondrial DNA. The results indicated a synergistic effect on spontaneous mutagenesis upon OGG1 and CCC2 double inactivation, placing 8-oxoguanine as a strong lesion-candidate at the origin of spontaneous mutations. The ccc2 mutant was more sensitive to cell killing and to mutagenesis upon 4-NQO challenge than the other studied strains. However, Ogg1 repair of exogenous-induced DNA damage revealed to be toxic and mutagenic to ccc2 deficient cells, which can be due to a detrimental action of Ogg1 on DNA lesions induced in ccc2 cells. Altogether, our results point to a critical and ambivalent role of BER mediated by Ogg1 in the maintenance of genomic stability in eukaryotes deficient in CCC2 gene.
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Affiliation(s)
- Claudia R da Silva
- Laboratório de Radio e Fotobiologia, Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, UERJ, Rio de Janeiro CEP 20551-030, Brasil, Laboratório de Radiobiologia Molecular; Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro CEP 21.941-902, Brasil and
| | - Gabriella S Almeida
- Laboratório de Radio e Fotobiologia, Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, UERJ, Rio de Janeiro CEP 20551-030, Brasil, Laboratório de Radiobiologia Molecular; Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro CEP 21.941-902, Brasil and Laboratório de Microbiologia e Avaliação Genotóxica, Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, UFRJ, Rio de Janeiro CEP 21.941-902, Brasil
| | - Adriano Caldeira-de-Araújo
- Laboratório de Radio e Fotobiologia, Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, UERJ, Rio de Janeiro CEP 20551-030, Brasil
| | - Alvaro C Leitão
- Laboratório de Radiobiologia Molecular; Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro CEP 21.941-902, Brasil and
| | - Marcelo de Pádula
- Laboratório de Radiobiologia Molecular; Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro CEP 21.941-902, Brasil and Laboratório de Microbiologia e Avaliação Genotóxica, Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, UFRJ, Rio de Janeiro CEP 21.941-902, Brasil
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14
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Cd/Hg cationic substitution in magic-sized CdSe clusters: Optical characterization and theoretical studies. Chem Phys 2015. [DOI: 10.1016/j.chemphys.2015.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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15
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Protesescu L, Nachtegaal M, Voznyy O, Borovinskaya O, Rossini AJ, Emsley L, Copéret C, Günther D, Sargent EH, Kovalenko MV. Atomistic description of thiostannate-capped CdSe nanocrystals: retention of four-coordinate SnS4 motif and preservation of Cd-rich stoichiometry. J Am Chem Soc 2015; 137:1862-74. [PMID: 25597625 PMCID: PMC4525771 DOI: 10.1021/ja510862c] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Colloidal semiconductor nanocrystals (NCs) are widely studied as building blocks for novel solid-state materials. Inorganic surface functionalization, used to displace native organic capping ligands from NC surfaces, has been a major enabler of electronic solid-state devices based on colloidal NCs. At the same time, very little is known about the atomistic details of the organic-to-inorganic ligand exchange and binding motifs at the NC surface, severely limiting further progress in designing all-inorganic NCs and NC solids. Taking thiostannates (K4SnS4, K4Sn2S6, K6Sn2S7) as typical examples of chalcogenidometallate ligands and oleate-capped CdSe NCs as a model NC system, in this study we address these questions through the combined application of solution (1)H NMR spectroscopy, solution and solid-state (119)Sn NMR spectroscopy, far-infrared and X-ray absorption spectroscopies, elemental analysis, and by DFT modeling. We show that through the X-type oleate-to-thiostannate ligand exchange, CdSe NCs retain their Cd-rich stoichiometry, with a stoichiometric CdSe core and surface Cd adatoms serving as binding sites for terminal S atoms of the thiostannates ligands, leading to all-inorganic (CdSe)core[Cdm(Sn2S7)yK(6y-2m)]shell (taking Sn2S7(6-) ligand as an example). Thiostannates SnS4(4-) and Sn2S7(6-) retain (distorted) tetrahedral SnS4 geometry upon binding to NC surface. At the same time, experiments and simulations point to lower stability of Sn2S6(4-) (and SnS3(2-)) in most solvents and its lower adaptability to the NC surface caused by rigid Sn2S2 rings.
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Affiliation(s)
- Loredana Protesescu
- Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich , Vladimir Prelog Weg 1, Zurich CH-8093, Switzerland
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16
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Han G, Ferranco A, Feng X, Chen Z, Kraatz H. Synthesis, Characterization of Some Ferrocenoyl Cysteine and Histidine Conjugates, and Their Interactions with Some Metal Ions. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201402470] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Guo‐Cheng Han
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin 541004, P. R. China, http://rsc.guet.edu.cn/RSC/public/show.aspx?par2=0014&par=864
| | - Annaleizle Ferranco
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada, http://www.utsc.utoronto.ca/~bkraatz/
| | - Xiao‐Zhen Feng
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin 541004, P. R. China, http://rsc.guet.edu.cn/RSC/public/show.aspx?par2=0014&par=864
| | - Zhencheng Chen
- School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin 541004, P. R. China, http://rsc.guet.edu.cn/RSC/public/show.aspx?par2=0014&par=864
| | - Heinz‐Bernhard Kraatz
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada, http://www.utsc.utoronto.ca/~bkraatz/
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Chang P, Cheng H, Li W, Zhuo L, He L, Yu Y, Zhao F. Photocatalytic reduction of o-chloronitrobenzene under visible light irradiation over CdS quantum dot sensitized TiO2. Phys Chem Chem Phys 2014; 16:16606-14. [DOI: 10.1039/c4cp01250j] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
CdS QDs-P25 was prepared by tethering CdS QDs with P25 through l-cysteine, and exhibited excellent photocatalytic activity under visible light. The photocatalytic reduction mechanism over CdS QDs-P25 was found to be a hydrogen transfer process between o-CNB and HCOOH molecules.
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Affiliation(s)
- Pingjing Chang
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, PR China
- Laboratory of Green Chemistry and Process
| | - Haiyang Cheng
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, PR China
- Laboratory of Green Chemistry and Process
| | - Wei Li
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, PR China
- Laboratory of Green Chemistry and Process
| | - Linhai Zhuo
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, PR China
- Laboratory of Green Chemistry and Process
| | - Limin He
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, PR China
- Laboratory of Green Chemistry and Process
| | - Yancun Yu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, PR China
- Laboratory of Green Chemistry and Process
| | - Fengyu Zhao
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, PR China
- Laboratory of Green Chemistry and Process
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18
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Chen S, Tian J, Jiang Y, Zhao Y, Zhang J, Zhao S. A one-step selective fluorescence turn-on detection of cysteine and homocysteine based on a facile CdTe/CdS quantum dots–phenanthroline system. Anal Chim Acta 2013; 787:181-8. [DOI: 10.1016/j.aca.2013.05.048] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 05/24/2013] [Accepted: 05/27/2013] [Indexed: 01/02/2023]
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19
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Parsons JG, Dokken KM, McClure J, Gardea-Torresdey JL. FTIR, XAS, and XRD study of cadmium complexes with l-cysteine. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.04.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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Leung BO, Jalilehvand F, Mah V, Parvez M, Wu Q. Silver(I) complex formation with cysteine, penicillamine, and glutathione. Inorg Chem 2013; 52:4593-602. [PMID: 23556419 PMCID: PMC3684387 DOI: 10.1021/ic400192c] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The complex formation between silver(I) and cysteine (H2Cys), penicillamine (H2Pen), and glutathione (H3Glu) in alkaline aqueous solution was examined using extended X-ray absorption fine structure (EXAFS) and (109)Ag NMR spectroscopic techniques. The complexes formed in 0.1 mol dm(-3) Ag(I) solutions with cysteine and penicillamine were investigated for ligand/Ag(I) (L/Ag) mole ratios increasing from 2.0 to 10.0. For the series of cysteine solutions (pH 10-11) a mean Ag-S bond distance of 2.45 ± 0.02 Å consistently emerged, while for penicillamine (pH 9) the average Ag-S bond distance gradually increased from 2.40 to 2.44 ± 0.02 Å. EXAFS and (109)Ag NMR spectra of a concentrated Ag(I)-cysteine solution (C(Ag(I)) = 0.8 mol dm(-3), L/Ag = 2.2) showed a mean Ag-S bond distance of 2.47 ± 0.02 Å and δ((109)Ag) 1103 ppm, consistent with prevailing, partially oligomeric AgS3 coordinated species, while for penicillamine (C(Ag(I)) = 0.5 mol dm(-3), L/Ag = 2.0) the mean Ag-S bond distance of 2.40 ± 0.02 Å and δ((109)Ag) 922 ppm indicate that mononuclear AgS2 coordinated complexes dominate. For Ag(I)-glutathione solutions (C(Ag(I)) = 0.01 mol dm(-3), pH ∼11), mononuclear AgS2 coordinated species with a mean Ag-S bond distance of 2.36 ± 0.02 Å dominate for L/Ag mole ratios from 2.0 to 10.0. The crystal structure of the silver(I)-cysteine compound (NH4)Ag2(HCys)(Cys)·H2O (1) precipitating at pH ∼10 was solved and showed a layer structure with both AgS3 and AgS3N coordination to the cysteinate ligands. A redetermination of the crystal structure of Ag(HPen)·H2O (2) confirmed the proposed digonal AgS2 coordination environment to bridging thiolate sulfur atoms in polymeric intertwining chains forming a double helix. A survey of Ag-S bond distances for crystalline Ag(I) complexes with S-donor ligands in different AgS2, AgS2(O/N), and AgS3 coordination environments was used, together with a survey of (109)Ag NMR chemical shifts, to assist assignments of the Ag(I) coordination in solution.
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21
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Vita N, Brubach JB, Hienerwadel R, Bremond N, Berthomieu D, Roy P, Berthomieu C. Electrochemically Induced Far-Infrared Difference Spectroscopy on Metalloproteins Using Advanced Synchrotron Technology. Anal Chem 2013; 85:2891-8. [DOI: 10.1021/ac303511g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Nicolas Vita
- Lab Interactions Protein Metal, Commissariat à l’Energie Atomique (CEA), DSV, IBEB, Saint-Paul-lez-Durance,
F-13108, France
- Centre National de la Recherche Scientifique, UMR Biol Veget et Microbiol
Environ, Saint-Paul-lez-Durance, F-13108, France
- Aix-Marseille Université, Saint-Paul-lez-Durance, F-13108, France
- Société Civile Synchrotron SOLEIL, L’Orme des Merisiers,
St-Aubin BP48, 91192 Gif-sur-Yvette Cedex, France
| | - Jean-Blaise Brubach
- Société Civile Synchrotron SOLEIL, L’Orme des Merisiers,
St-Aubin BP48, 91192 Gif-sur-Yvette Cedex, France
| | - Rainer Hienerwadel
- Centre National de la Recherche Scientifique, UMR Biol Veget et Microbiol
Environ, Saint-Paul-lez-Durance, F-13108, France
- Lab Genet Biophys Plantes, Aix-Marseille Université, Marseille, F-13009,
France
- Commissariat à l’Energie Atomique (CEA), DSV, IBEB, Marseille,
F-13009, France
| | - Nicolas Bremond
- Lab Interactions Protein Metal, Commissariat à l’Energie Atomique (CEA), DSV, IBEB, Saint-Paul-lez-Durance,
F-13108, France
- Centre National de la Recherche Scientifique, UMR Biol Veget et Microbiol
Environ, Saint-Paul-lez-Durance, F-13108, France
- Aix-Marseille Université, Saint-Paul-lez-Durance, F-13108, France
| | - Dorothée Berthomieu
- Institut Charles Gerhardt, MACS, UMR 5253 CNRS-ENSCM-UM1-UM2, 8, rue
de l’Ecole Normale, 34296 Montpellier Cedex 5, France
| | - Pascale Roy
- Société Civile Synchrotron SOLEIL, L’Orme des Merisiers,
St-Aubin BP48, 91192 Gif-sur-Yvette Cedex, France
| | - Catherine Berthomieu
- Lab Interactions Protein Metal, Commissariat à l’Energie Atomique (CEA), DSV, IBEB, Saint-Paul-lez-Durance,
F-13108, France
- Centre National de la Recherche Scientifique, UMR Biol Veget et Microbiol
Environ, Saint-Paul-lez-Durance, F-13108, France
- Aix-Marseille Université, Saint-Paul-lez-Durance, F-13108, France
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22
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Zaytsev DV, Morozov VA, Fan J, Zhu X, Mukherjee M, Ni S, Kennedy MA, Ogawa MY. Metal-binding properties and structural characterization of a self-assembled coiled coil: Formation of a polynuclear Cd–thiolate cluster. J Inorg Biochem 2013; 119:1-9. [DOI: 10.1016/j.jinorgbio.2012.10.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 10/22/2012] [Accepted: 10/23/2012] [Indexed: 01/10/2023]
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23
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24
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Kwan DCH, Prole DL, Yellen G. Structural changes during HCN channel gating defined by high affinity metal bridges. ACTA ACUST UNITED AC 2012; 140:279-91. [PMID: 22930802 PMCID: PMC3434101 DOI: 10.1085/jgp.201210838] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide–sensitive nonselective cation (HCN) channels are activated by membrane hyperpolarization, in contrast to the vast majority of other voltage-gated channels that are activated by depolarization. The structural basis for this unique characteristic of HCN channels is unknown. Interactions between the S4–S5 linker and post-S6/C-linker region have been implicated previously in the gating mechanism of HCN channels. We therefore introduced pairs of cysteines into these regions within the sea urchin HCN channel and performed a Cd2+-bridging scan to resolve their spatial relationship. We show that high affinity metal bridges between the S4–S5 linker and post-S6/C-linker region can induce either a lock-open or lock-closed phenotype, depending on the position of the bridged cysteine pair. This suggests that interactions between these regions can occur in both the open and closed states, and that these regions move relative to each other during gating. Concatenated constructs reveal that interactions of the S4–S5 linker and post-S6/C-linker can occur between neighboring subunits. A structural model based on these interactions suggests a mechanism for HCN channel gating. We propose that during voltage-dependent activation the voltage sensors, together with the S4–S5 linkers, drive movement of the lower ends of the S5 helices around the central axis of the channel. This facilitates a movement of the pore-lining S6 helices, which results in opening of the channel. This mechanism may underlie the unique voltage dependence of HCN channel gating.
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Affiliation(s)
- Daniel C H Kwan
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
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25
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Jalilehvand F, Amini Z, Parmar K. Cadmium(II) complex formation with selenourea and thiourea in solution: an XAS and 113Cd NMR study. Inorg Chem 2012; 51:10619-30. [PMID: 23016594 PMCID: PMC3498765 DOI: 10.1021/ic300852t] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The complexes formed in methanol solutions of Cd(CF(3)SO(3))(2) with selenourea (SeU) or thiourea (TU), for thiourea also in aqueous solution, were studied by combining (113)Cd NMR and X-ray absorption spectroscopy. At low temperature (~200 K), distinct (113)Cd NMR signals were observed, corresponding to CdL(n)(2+) species (n = 0-4, L = TU or SeU) in slow ligand exchange. Peak integrals were used to obtain the speciation in the methanol solutions, allowing stability constants to be estimated. For cadmium(II) complexes with thione (C═S) or selone (C═Se) groups coordinated in Cd(S/Se)O(5) or Cd(S/Se)(2)O(4) (O from MeOH or CF(3)SO(3)(-)) environments, the (113)Cd chemical shifts were quite similar, within 93-97 ppm and 189-193 ppm, respectively. However, the difference in the chemical shift for the Cd(SeU)(4)(2+) (578 pm) and Cd(TU)(4)(2+) (526 ppm) species, with CdSe(4) and CdS(4) coordination, respectively, shows less chemical shielding for the coordinated Se atoms than for S, in contrast to the common trend with increasing shielding in the following order: O > N > Se > S. In solutions dominated by mono- and tetra-thiourea/selenourea complexes, their coordination and bond distances could be evaluated by Cd K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy. At ~200 K and high excess of thiourea, a minor amount (up to ~30%) of [Cd(TU)(5-6)](2+) species was detected by an upfield shift of the (113)Cd NMR signal (up to 423 ppm) and an amplitude reduction of the EXAFS oscillation. The amount was estimated by fitting linear combinations of simulated EXAFS spectra for [Cd(TU)(4)](2+) and [Cd(TU)(6)](2+) complexes. At room temperature, [Cd(TU)(4)](2+) was the highest complex formed, also in aqueous solution. Cd L(3)-edge X-ray absorption near edge structure (XANES) spectra of cadmium(II) thiourea solutions in methanol were used to follow changes in the CdS(x)O(y) coordination. The correlations found from the current and previous studies between (113)Cd NMR chemical shifts and different Cd(II) coordination environments are generally useful for evaluating cadmium coordination to thione-containing or Se-donor ligands in biochemical systems or for monitoring speciation in solution.
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Affiliation(s)
- Farideh Jalilehvand
- Department of Chemistry, University of Calgary, Calgary, AB, Canada T2N 1N4.
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26
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Bargiello TA, Tang Q, Oh S, Kwon T. Voltage-dependent conformational changes in connexin channels. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1818:1807-22. [PMID: 21978595 PMCID: PMC3367129 DOI: 10.1016/j.bbamem.2011.09.019] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 09/09/2011] [Accepted: 09/17/2011] [Indexed: 10/17/2022]
Abstract
Channels formed by connexins display two distinct types of voltage-dependent gating, termed V(j)- or fast-gating and loop- or slow-gating. Recent studies, using metal bridge formation and chemical cross-linking have identified a region within the channel pore that contributes to the formation of the loop-gate permeability barrier. The conformational changes are remarkably large, reducing the channel pore diameter from 15 to 20Å to less than 4Å. Surprisingly, the largest conformational change occurs in the most stable region of the channel pore, the 3(10) or parahelix formed by amino acids in the 42-51 segment. The data provide a set of positional constraints that can be used to model the structure of the loop-gate closed state. Less is known about the conformation of the V(j)-gate closed state. There appear to be two different mechanisms; one in which conformational changes in channel structure are linked to a voltage sensor contained in the N-terminus of Cx26 and Cx32 and a second in which the C-terminus of Cx43 and Cx40 may act either as a gating particle to block the channel pore or alternatively to stabilize the closed state. The later mechanism utilizes the same domains as implicated in effecting pH gating of Cx43 channels. It is unclear if the two V(j)-gating mechanisms are related or if they represent different gating mechanisms that operate separately in different subsets of connexin channels. A model of the V(j)-closed state of Cx26 hemichannel that is based on the X-ray structure of Cx26 and electron crystallographic structures of a Cx26 mutation suggests that the permeability barrier for V(j)-gating is formed exclusively by the N-terminus, but recent information suggests that this conformation may not represent a voltage-closed state. Closed state models are considered from a thermodynamic perspective based on information from the 3.5Å Cx26 crystal structure and molecular dynamics (MD) simulations. The applications of computational and experimental methods to define the path of allosteric molecular transitions that link the open and closed states are discussed. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
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Affiliation(s)
- Thaddeus A Bargiello
- Dominic P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.
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Pathak RK, Hinge VK, Mahesh K, Rai A, Panda D, Rao CP. Cd2+ complex of a triazole-based calix[4]arene conjugate as a selective fluorescent chemosensor for Cys. Anal Chem 2012; 84:6907-13. [PMID: 22834792 DOI: 10.1021/ac301492h] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
An N,N-Dimethylamine ethylimino-appended triazole-linked calix[4]arene conjugate, L, has been synthesized and characterized, and its Cd(2+) complex has been isolated and characterized. The structure of [CdL] was established by computational calculation using B3LYP/LANL2DZ. Time-dependent density functional theory calculations were performed to demonstrate the electronic properties of [CdL]. This highly fluorescing [CdL] has been used to recognize Cys selectively among the 20 naturally occurring amino acids. [CdL] exhibits a minimum detection limit of 58 ppb for Cys, with reusability and reversibility being imparted to the system during sensing. Thus, the sensing of Cys was well demonstrated using various techniques, viz., fluorescence, absorption, visual color change, electrospray ionization MS, (1)H NMR, and live cell imaging experiments.
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Affiliation(s)
- Rakesh K Pathak
- Bioinorganic Laboratory, Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India
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Abstract
A structural investigation of complexes formed between the Pb(2+) ion and glutathione (GSH, denoted AH(3) in its triprotonated form), the most abundant nonprotein thiol in biological systems, was carried out for a series of aqueous solutions at pH 8.5 and C(Pb(2+)) = 10 mM and in the solid state. The Pb L(III)-edge extended X-ray absorption fine structure (EXAFS) oscillation for a solid compound with the empirical formula [Pb(AH(2))]ClO(4) was modeled with one Pb-S and two short Pb-O bond distances at 2.64 ± 0.04 and 2.28 ± 0.04 Å, respectively. In addition, Pb···Pb interactions at 4.15 ± 0.05 Å indicate dimeric species in a network where the thiolate group forms an asymmetrical bridge between two Pb(2+) ions. In aqueous solution at the mole ratio GSH/Pb(II) = 2.0 (C(Pb(2+)) = 10 mM, pH 8.5), lead(II) complexes with two thiolate ligands form, characterized by a ligand-to-metal charge-transfer band (LMCT) S(-) → Pb(2+) at 317 nm in the UV-vis spectrum and mean Pb-S and Pb-(N/O) bond distances of 2.65 ± 0.04 and 2.51 ± 0.04 Å, respectively, from a Pb L(III)-edge EXAFS spectrum. For solutions with higher mole ratios, GSH/Pb(II) ≥ 3.0, electrospray ionization mass spectroscopy spectra identified a triglutathionyllead(II) complex, for which Pb L(III)-edge EXAFS spectroscopy shows a mean Pb-S distance of 2.65 ± 0.04 Å in PbS(3) coordination, (207)Pb NMR spectroscopy displays a chemical shift of 2793 ppm, and in the UV-vis spectrum, an S(-) → Pb(2+) LMCT band appears at 335 nm. The complex persists at high excess of GSH and also at ∼25 K in frozen glycerol (33%)/water glasses for GSH/Pb(II) mole ratios from 4.0 to 10 (C(Pb(2+)) = 10 mM) measured by Pb L(III)-edge EXAFS spectroscopy.
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Affiliation(s)
- Vicky Mah
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
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Nevins JS, Coughlin KM, Watson DF. Attachment of CdSe nanoparticles to TiO2 via aqueous linker-assisted assembly: influence of molecular linkers on electronic properties and interfacial electron transfer. ACS APPLIED MATERIALS & INTERFACES 2011; 3:4242-4253. [PMID: 21970556 DOI: 10.1021/am200900c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
CdSe nanoparticles (NPs) capped with cysteinate (Cys), 3-mercaptopropionate (MP), and mercaptosuccinate (MS) were adsorbed to TiO(2) from basic aqueous dispersions. Native capping groups served as molecular linkers to TiO(2). Thus, the materials-assembly chemistry was simplified and made more reproducible and environmentally benign. The electronic properties of CdSe and the electron-transfer reactivity at CdSe-linker-TiO(2) interfaces varied with the structure and functionality of the capping groups. Cys-capped CdSe NPs exhibited a narrow and intense first excitonic absorption band centered at 422 nm, suggesting that they were magic-sized nanocrystals (MSCs) with diameters less than 2 nm. MP- and MS-capped CdSe NPs had broader and lower-energy absorption bands, which are typical of regular quantum dots. Photocurrent action spectra of nanocrystalline TiO(2) films functionalized with Cys-CdSe, MP-CdSe, and MS-CdSe overlaid closely with absorption spectra, indicating that excitation of CdSe gave rise to the injection of electrons into TiO(2). Under white-light illumination, the global energy-conversion efficiency for Cys-capped CdSe ((0.45 ± 0.11)%) was 1.2-to-6-fold greater than for MP- and MS-capped CdSe. Similarly, the absorbed photon-to-current efficiency was 1.3-to-3.3-fold greater. These differences arose from linker-dependent variations of electron-injection and charge-recombination reactivity. Transient absorption measurements indicated that electron injection from Cys-capped CdSe was more efficient than from MS-capped CdSe. In addition, charge recombination at CdSe-MS-TiO(2) interfaces was complete within hundreds of nanoseconds, whereas the charge-separated-state lifetime at CdSe-Cys-TiO(2) interfaces was on the order of several microseconds. Thus, Cys-capped CdSe MSCs are readily attached to TiO(2) and exhibit unusual electronic properties and desirable electron-transfer reactivity.
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Affiliation(s)
- Jeremy S Nevins
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, USA
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Hegde ML, Hegde PM, Rao KS, Mitra S. Oxidative genome damage and its repair in neurodegenerative diseases: function of transition metals as a double-edged sword. J Alzheimers Dis 2011; 24 Suppl 2:183-98. [PMID: 21441656 DOI: 10.3233/jad-2011-110281] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The neurons in the central nervous system (CNS) with high O2 consumption and prolonged life span are chronically exposed to high levels of reactive oxygen species (ROS). Accumulation of ROS-induced genome damage in the form of oxidized bases and single-strand breaks (SSBs) as well as their defective or reduced repair in the brain has been implicated in the etiology of various neurological disorders including Alzheimer's/Parkinson's diseases (AD/PD). Although inactivating mutations in some DNA repair genes have been linked to hereditary neurodegenerative diseases, the underlying mechanisms of repair deficiencies for the sporadic diseases is not understood. The ROS-induced DNA damage is predominantly repaired via the highly conserved and regulated base excision/SSB repair (BER/SSBR) pathway. We recently made an interesting discovery that the transition metals iron and copper, which accumulate excessively in the brains of AD, PD, and other neurodegenerative diseases, act as a 'double-edged sword' by inducing genotoxic ROS and inhibiting DNA damage repair at the same time. These metals inhibit the base excision activity of NEIL family DNA glycosylases by oxidizing them, changing their structure, and inhibiting their binding to downstream repair proteins. Metal chelators and reducing agents partially reverse the inhibition, while curcumin with both chelating and reducing activities reverses the inhibition nearly completely. In this review, we have discussed the possible etiological linkage of BER/SSBR defects to neurodegenerative diseases and the therapeutic potential of metal chelators in restoring DNA repair capacity.
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Affiliation(s)
- Muralidhar L Hegde
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-1079, USA.
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Quantum chemical studies on the role of water microsolvation in interactions between group 12 metal species (Hg2+, Cd2+, and Zn2+) and neutral and deprotonated cysteines. Theor Chem Acc 2011. [DOI: 10.1007/s00214-011-0975-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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32
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Jalilehvand F, Amini Z, Parmar K, Kang EY. Cadmium(ii) N-acetylcysteine complex formation in aqueous solution. Dalton Trans 2011; 40:12771-8. [DOI: 10.1039/c1dt11705j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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33
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Hegde ML, Hegde PM, Holthauzen LMF, Hazra TK, Rao KSJ, Mitra S. Specific Inhibition of NEIL-initiated repair of oxidized base damage in human genome by copper and iron: potential etiological linkage to neurodegenerative diseases. J Biol Chem 2010; 285:28812-25. [PMID: 20622253 PMCID: PMC2937909 DOI: 10.1074/jbc.m110.126664] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 07/06/2010] [Indexed: 11/06/2022] Open
Abstract
Dyshomeostasis of transition metals iron and copper as well as accumulation of oxidative DNA damage have been implicated in multitude of human neurodegenerative diseases, including Alzheimer disease and Parkinson disease. These metals oxidize DNA bases by generating reactive oxygen species. Most oxidized bases in mammalian genomes are repaired via the base excision repair pathway, initiated with one of four major DNA glycosylases: NTH1 or OGG1 (of the Nth family) or NEIL1 or NEIL2 (of the Nei family). Here we show that Fe(II/III) and Cu(II) at physiological levels bind to NEIL1 and NEIL2 to alter their secondary structure and strongly inhibit repair of mutagenic 5-hydroxyuracil, a common cytosine oxidation product, both in vitro and in neuroblastoma (SH-SY5Y) cell extract by affecting the base excision and AP lyase activities of NEILs. The specificity of iron/copper inhibition of NEILs is indicated by a lack of similar inhibition of OGG1, which also indicated that the inhibition is due to metal binding to the enzymes and not DNA. Fluorescence and surface plasmon resonance studies show submicromolar binding of copper/iron to NEILs but not OGG1. Furthermore, Fe(II) inhibits the interaction of NEIL1 with downstream base excision repair proteins DNA polymerase beta and flap endonuclease-1 by 4-6-fold. These results indicate that iron/copper overload in the neurodegenerative diseases could act as a double-edged sword by both increasing oxidative genome damage and preventing their repair. Interestingly, specific chelators, including the natural chemopreventive compound curcumin, reverse the inhibition of NEILs both in vitro and in cells, suggesting their therapeutic potential.
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Affiliation(s)
| | - Pavana M. Hegde
- From the Department of Biochemistry and Molecular Biology and
| | | | - Tapas K. Hazra
- From the Department of Biochemistry and Molecular Biology and
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, Texas 77555 and
| | - K. S. Jagannatha Rao
- the Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore 570020, India
| | - Sankar Mitra
- From the Department of Biochemistry and Molecular Biology and
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Jalilehvand F, Leung BO, Mah V. Cadmium(II) complex formation with cysteine and penicillamine. Inorg Chem 2010; 48:5758-71. [PMID: 19469490 DOI: 10.1021/ic802278r] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The complex formation between cadmium(II) and the ligands cysteine (H(2)Cys) and penicillamine (H(2)Pen = 3,3'-dimethylcysteine) in aqueous solutions, having C(Cd(II)) approximately 0.1 mol dm(-3) and C(H(2)L) = 0.2-2 mol dm(-3), was studied at pH = 7.5 and 11.0 by means of (113)Cd NMR and Cd K- and L(3)-edge X-ray absorption spectroscopy. For all cadmium(II)-cysteine molar ratios, the mean Cd-S and Cd-(N/O) bond distances were found in the ranges 2.52-2.54 and 2.27-2.35 A, respectively. The corresponding cadmium(II)-penicillamine complexes showed slightly shorter Cd-S bonds, 2.50-2.53 A, but with the Cd-(N/O) bond distances in a similar wide range, 2.28-2.33 A. For the molar ratio C(H(2)L)/C(Cd(II)) = 2, the (113)Cd chemical shifts, in the range 509-527 ppm at both pH values, indicated complexes with distorted tetrahedral CdS(2)N(N/O) coordination geometry. With a large excess of cysteine (molar ratios C(H(2)Cys)/C(Cd(II)) >or= 10), complexes with CdS(4) coordination geometry dominate, consistent with the (113)Cd NMR chemical shifts, delta approximately 680 ppm at pH 7.5 and 636-658 ppm at pH 11.0, and their mean Cd-S distances were 2.53 +/- 0.02 A. At pH 7.5, the complexes are almost exclusively sulfur-coordinated as [Cd(S-cysteinate)(4)](n-), while at higher pH, the deprotonation of the amine groups promotes chelate formation. At pH 11.0, a minor amount of the [Cd(Cys)(3)](4-) complex with CdS(3)N coordination is formed. For the corresponding penicillamine solutions with molar ratios C(H(2)Pen)/C(Cd(II)) >or= 10, the (113)Cd NMR chemical shifts, delta approximately 600 ppm at pH 7.5 and 578 ppm at pH 11.0, together with the average bond distances, Cd-S 2.53 +/- 0.02 A and Cd-(N/O) 2.30-2.33 A, indicate that [Cd(penicillaminate)(3)](n-) complexes with chelating CdS(3)(N/O) coordination dominate already at pH 7.5 and become mixed with CdS(2)N(N/O) complexes at pH 11.0. The present study reveals differences between cysteine and penicillamine as ligands to the cadmium(II) ion that can explain why cysteine-rich metallothionines are capable of capturing cadmium(II) ions, while penicillamine, clinically useful for treating the toxic effects of mercury(II) and lead(II) exposure, is not efficient against cadmium(II) poisoning.
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Affiliation(s)
- Farideh Jalilehvand
- Department of Chemistry, University of Calgary, Calgary, AB, Canada T2N 1N4.
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Mah V, Jalilehvand F. Cadmium(II) complex formation with glutathione. J Biol Inorg Chem 2009; 15:441-58. [PMID: 20035360 DOI: 10.1007/s00775-009-0616-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Accepted: 12/04/2009] [Indexed: 11/24/2022]
Abstract
Complex formation between heavy metal ions and glutathione (GSH) is considered as the initial step in many detoxification processes in living organisms. In this study the structure and coordination between the cadmium(II) ion and GSH were investigated in aqueous solutions (pH 7.5 and 11.0) and in the solid state, using a combination of spectroscopic techniques. The similarity of the Cd K-edge and L(3)-edge X-ray absorption spectra of the solid compound [Cd(GS)(GSH)]ClO(4).3H(2)O, precipitating at pH 3.0, with the previously studied cysteine compound {Cd(HCys)(2).H(2)O}(2).H(3)O(+).ClO(4) (-) corresponds to Cd(S-GS)(3)O (dominating) and Cd(S-GS)(4) four-coordination within oligomeric complexes with mean bond distances of 2.51 +/- 0.02 A for Cd-S and 2.24 +/- 0.04 A for Cd-O. For cadmium(II) solutions (C (Cd(II)) approximately 0.05 M) at pH 7.5 with moderate excess of GSH (C (GSH)/C (Cd(II)) = 3.0-5.0), a mix of Cd(S-GS)(3)O (dominating) and Cd(S-GS)(4) species is consistent with the broad (113)Cd NMR resonances in the range 632-658 ppm. In alkaline solutions (pH 11.0 and C (GSH)/C (Cd(II)) = 2.0 or 3.0), two distinct peaks at 322 and 674 ppm are obtained. The first peak indicates six-coordinated mononuclear and dinuclear complexes with CdS(2)N(2)(N/O)(2) and CdSN(3)O(2) coordination in fast exchange, whereas the second corresponds to Cd(S-GS)(4) sites. At high ligand excess the tetrathiolate complex, Cd(S-GS)(4), characterized by a sharp delta((113)Cd) NMR signal at 677 ppm, predominates. The average Cd-S distance, obtained from the X-ray absorption spectra, varied within a narrow range, 2.49-2.53 A, for all solutions (pH 7.5 and 11.0) regardless of the coordination geometry.
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Affiliation(s)
- Vicky Mah
- Department of Chemistry, University of Calgary, Calgary, AB, T2N 1N4, Canada
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