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Nature Communications Apr 2015Carotenes are naturally abundant unsaturated hydrocarbon pigments, and their fascinating physical and chemical properties have been studied intensively not only for...
Carotenes are naturally abundant unsaturated hydrocarbon pigments, and their fascinating physical and chemical properties have been studied intensively not only for better understanding of the roles in biological processes but also for the use in artificial chemical systems. However, their metal-binding ability has been virtually unexplored. Here we report that β-carotene has the ability to assemble and align ten metal atoms to afford decanuclear homo- and heterometal chain complexes. The metallo-carotenoid framework shows reversible metalation-demetalation reactivity with multiple metals, which allows us to control the size of metal chains as well as the heterobimetallic composition and arrangement of the carotene-supported metal chains.
Topics: Chelating Agents; Coordination Complexes; Crystallography, X-Ray; Magnetic Resonance Spectroscopy; Molecular Conformation; Palladium; Platinum; beta Carotene
PubMed: 25857402
DOI: 10.1038/ncomms7742 -
Microbiology Spectrum Apr 2016Bacteria are one of the premier biological forces that, in combination with chemical and physical forces, drive metal availability in the environment. Bacterial spores,... (Review)
Review
Bacteria are one of the premier biological forces that, in combination with chemical and physical forces, drive metal availability in the environment. Bacterial spores, when found in the environment, are often considered to be dormant and metabolically inactive, in a resting state waiting for favorable conditions for them to germinate. However, this is a highly oversimplified view of spores in the environment. The surface of bacterial spores represents a potential site for chemical reactions to occur. Additionally, proteins in the outer layers (spore coats or exosporium) may also have more specific catalytic activity. As a consequence, bacterial spores can play a role in geochemical processes and may indeed find uses in various biotechnological applications. The aim of this review is to introduce the role of bacteria and bacterial spores in biogeochemical cycles and their potential use as toxic metal bioremediation agents.
Topics: Bacteria; Environmental Restoration and Remediation; Metals; Spores, Bacterial
PubMed: 27227313
DOI: 10.1128/microbiolspec.TBS-0018-2013 -
Cell Chemical Biology Jul 2018Shared molecular pathologies between distinct neurodegenerative disorders offer unique opportunities to identify common mechanisms of neuron death, and apply lessons... (Review)
Review
Shared molecular pathologies between distinct neurodegenerative disorders offer unique opportunities to identify common mechanisms of neuron death, and apply lessons learned from one disease to another. Neurotoxic superoxide dismutase 1 (SOD1) proteinopathy in SOD1-associated familial amyotrophic lateral sclerosis (fALS) is recapitulated in idiopathic Parkinson disease (PD), suggesting that these two phenotypically distinct disorders share an etiological pathway, and tractable therapeutic target(s). Despite 25 years of research, the molecular determinants underlying SOD1 misfolding and toxicity in fALS remain poorly understood. The absence of SOD1 mutations in PD highlights mounting evidence that SOD1 mutations are not the sole cause of SOD1 protein misfolding occasioning oligomerization and toxicity, reinforcing the importance of non-genetic factors, including protein metallation and post-translational modification in determining SOD1 stability and function. We propose that these non-genetic factors underlie the misfolding and dysfunction of SOD1 and other proteins in both PD and fALS, constituting a shared and tractable pathway to neurodegeneration.
Topics: Animals; Homeostasis; Humans; Metals; Movement Disorders; Mutation; Oxidative Stress; Superoxide Dismutase-1
PubMed: 29861271
DOI: 10.1016/j.chembiol.2018.05.004 -
The Journal of Biological Chemistry Apr 2012Eukaryotic cells contain hundreds of metalloproteins, and ensuring that each protein receives the correct metal ion is a critical task for cells. Recent work in budding... (Review)
Review
Eukaryotic cells contain hundreds of metalloproteins, and ensuring that each protein receives the correct metal ion is a critical task for cells. Recent work in budding yeast and mammalian cells has uncovered a system of iron delivery operating in the cytosolic compartment that involves monothiol glutaredoxins, which bind iron in the form of iron-sulfur clusters, and poly(rC)-binding proteins, which bind Fe(II) directly. In yeast cells, cytosolic monothiol glutaredoxins are required for the formation of heme and iron-sulfur clusters and the metallation of some non-heme iron enzymes. Poly(rC)-binding proteins can act as iron chaperones, delivering iron to target non-heme enzymes through direct protein-protein interactions. Although the molecular details have yet to be explored, these proteins, acting independently or together, may represent the basic cellular machinery for intracellular iron delivery.
Topics: Animals; Biological Transport; Cytosol; Enzymes; Glutaredoxins; Heme; Humans; Iron; Iron-Binding Proteins; Iron-Sulfur Proteins; Metalloproteins; Metals; Models, Biological; Molecular Chaperones; Sulfhydryl Compounds; Frataxin
PubMed: 22389494
DOI: 10.1074/jbc.R111.326876 -
Environmental Research Oct 2019Emerging evidence suggests airborne metals may be associated with breast cancer risk. However, breast cancer is heterogenous and associations with heavy metals vary by...
BACKGROUND
Emerging evidence suggests airborne metals may be associated with breast cancer risk. However, breast cancer is heterogenous and associations with heavy metals vary by subtype. Heavy metals possess both carcinogenic and xenoestrogenic properties which may be related to different tumor etiologies. Therefore, we tested for etiologic heterogeneity, using a case-series approach, to determine whether associations between residential airborne metal concentrations and breast cancer differed by tumor subtype.
METHODS
Between 2005 and 2008, we enrolled incident breast cancer cases into the Breast Cancer Care in Chicago study. Tumor estrogen and progesterone receptors status was determined by medical record abstraction and confirmed immunohistochemically (N = 696; 147 ER/PR-negative). The 2002 USEPA's National Air Toxics Assessment census-tract estimates of metal concentrations (antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, mercury, nickel and selenium) were matched to participants' residences of the same year. Adjusted logistic regression models were used to examine whether the airborne heavy metal associations differed by tumor ER/PR status. Principal component analysis was performed to assess associations by metal co-exposures.
RESULTS
Comparing the highest and lowest quintiles, higher concentrations of antimony (odds ratio[OR]: 1.8, 95% confidence interval[CI]: 0.9, 3.7, P-trend: 0.05), cadmium (OR: 2.3, 95% CI: 1.2, 4.4, P-trend: 0.04) and cobalt (OR: 2.0, 95% CI: 0.9, 4.4, P-trend: 0.04) were associated with ER/PR-negative breast cancer. Mixture analysis using principal components suggested co-exposures to multiple airborne heavy metals may drive associations with tumor receptor status.
CONCLUSIONS
Among women diagnosed with breast cancer, metallic air pollutants were associated with increased odds of developing ER/PR-negative breast cancer.
Topics: Air Pollutants; Air Pollution; Breast; Breast Neoplasms; Cadmium; Environmental Exposure; Female; Humans; Metals, Heavy; Risk Factors
PubMed: 31419716
DOI: 10.1016/j.envres.2019.108639 -
Zhejiang Da Xue Xue Bao. Yi Xue Ban =... Sep 2015Because of the excellent mechanical properties, biocompatibility and reasonable prices, biomedical metallic materials are widely used in the manufacture of vascular... (Review)
Review
Because of the excellent mechanical properties, biocompatibility and reasonable prices, biomedical metallic materials are widely used in the manufacture of vascular stents, heart valve membrane, artificial joints and other body implants. However, the physiological environment in the body is very complex, the long-term embedding of the metal implants may result in corrosion or some nonspecific effects. The properties of medical metal surfaces may decay, which can cause serious injury to human body. By means of the self-assembled monolayer(SAM) technology, the physical and chemical properties of the medical metal surfaces can be modified, and through the SAM medium, some functional materials can be grafted on the metal surfaces, which can largely improve the stability and compatibility of implants in the body, and find wide applications in promoting cell adhesion, improving hemocompatibility, inhibiting bacteria growth, and constructing drug delivery coatings. This paper reviews the progress in the application of SAM in biomedical metallic materials.
Topics: Biocompatible Materials; Cell Adhesion; Corrosion; Humans; Metals; Prostheses and Implants; Stents
PubMed: 26713537
DOI: 10.3785/j.issn.1008-9292.2015.09.19 -
Environmental Monitoring and Assessment Jun 2023We demonstrated the metal accumulation potential of Amaranthus retorflexus, a European weed species, both in moderately and strongly metal-contaminated sites. Metal...
We demonstrated the metal accumulation potential of Amaranthus retorflexus, a European weed species, both in moderately and strongly metal-contaminated sites. Metal accumulation in roots, stems, and leaves were studied. We also calculated the bioaccumulation factor (BAF), and translocation factor (TF) values to quantify the metal accumulation, and translocation between plant organs. Our findings indicated that metal accumulation correlated with metal concentration; that is plant organs accumulated higher concentration of metals in the contaminated area than in the control one. We found that the concentrations of Ba, Mn, Sr and Zn were the highest in leaves, and Al, Cr, Cu, Fe and Pb in roots. High BAF value was found for Sr in all studied areas, indicating this metal's high accumulation potential of Amaranthus retorflexus. High TF values were found for Al, Ba, Cu, Fe, Mn, Sr and Zn; these metals were successfully transported to aboveground plant organs. We demonstrated that A. retroflexus, a fast-growing, rapidly spreading weed in Europe, was especially useful for heavy metal phytoremediation and phytoextraction.
Topics: Biodegradation, Environmental; Plant Weeds; Amaranthus; Introduced Species; Environmental Monitoring; Soil Pollutants; Metals, Heavy; Europe; Plant Roots; Soil
PubMed: 37261518
DOI: 10.1007/s10661-023-11422-3 -
International Journal of Environmental... Mar 2021Mining and petroleum production are the source of many elements and base materials fundamental for our modern way of life. The flip side of these keystone industries is...
Mining and petroleum production are the source of many elements and base materials fundamental for our modern way of life. The flip side of these keystone industries is the environmental degradation they can cause if not properly managed. Metallic mining and petroleum production can contaminate the local ecosystem with sediments, chemicals used in the industrial processes and heavy metals, part of the metallic ore or oil reservoir. The objective of this project was to analyze the spatial distribution of the presence of different potentially hazardous elements that make up the metallic deposits and oil reservoirs in Ecuador, focused mainly on artisanal and small-scale gold mining (ASGM) districts. Additionally, we were interested in analyzing this information under the local political and administrative contexts which are key to determining how likely it is that mismanagement of the local mineral deposits and petroleum exploitation projects will end up causing environmental degradation. An extensive and intensive literature search was conducted for information on the presence and concentration of 19 potentially harmful elements. We analyzed data on 11 metallic deposits throughout Ecuador and a major oilfield in the Ecuadorian Amazon basin. We used geographic information systems to analyze the spatial distribution of these reservoirs and their mineral compositions. The results indicated a widespread distribution and high concentration of elements potentially harmful for human health, such as mercury, cadmium and arsenic, throughout the metallic deposits in Ecuador. This is particularly true for long-exploited ASGM districts, such as Ponce-Enríquez, Portovelo-Zaruma and Nambija. This study highlights the importance of understanding geological diversity and its potential risks to better protect the biological diversity and public health of its inhabitants. Furthermore, we consider our work not as a call to stop ASGM mining nor petroleum production, but on the contrary as a strong call to plan every mining and petroleum production project considering these risks. Moreover, our work is a call to action by the local government and authorities to stop corruption and fulfill their duties overseeing the activities of mining and petroleum companies, stopping illegal mining, helping ASGM communities to improve their environmental standards, finding alternative income sources and protecting the local environment.
Topics: Ecosystem; Ecuador; Environmental Monitoring; Gold; Humans; Mercury; Metals, Heavy; Mining; Petroleum
PubMed: 33801864
DOI: 10.3390/ijerph18062794 -
Nature Oct 2019Transition-metal complexes are widely used in the physical and biological sciences. They have essential roles in catalysis, synthesis, materials science, photophysics...
Transition-metal complexes are widely used in the physical and biological sciences. They have essential roles in catalysis, synthesis, materials science, photophysics and bioinorganic chemistry. Our understanding of transition-metal complexes originates from Alfred Werner's realization that their three-dimensional shape influences their properties and reactivity, and the intrinsic link between shape and electronic structure is now firmly underpinned by molecular-orbital theory. Despite more than a century of advances in this field, the geometries of transition-metal complexes remain limited to a few well-understood examples. The archetypal geometries of six-coordinate transition metals are octahedral and trigonal prismatic, and although deviations from ideal bond angles and bond lengths are frequent, alternative parent geometries are extremely rare. The hexagonal planar coordination environment is known, but it is restricted to condensed metallic phases, the hexagonal pores of coordination polymers, or clusters that contain more than one transition metal in close proximity. Such a geometry had been considered for [Ni(PBu)]; however, an analysis of the molecular orbitals suggested that this complex is best described as a 16-electron species with a trigonal planar geometry. Here we report the isolation and structural characterization of a simple coordination complex in which six ligands form bonds with a central transition metal in a hexagonal planar arrangement. The structure contains a central palladium atom surrounded by three hydride and three magnesium-based ligands. This finding has the potential to introduce additional design principles for transition-metal complexes, with implications for several scientific fields.
Topics: Coordination Complexes; Materials Science; Metals; Molecular Conformation; Transition Elements
PubMed: 31597960
DOI: 10.1038/s41586-019-1616-2 -
Biochemistry Aug 2016Iron, copper, zinc, manganese, cobalt, and molybdenum play important roles in mitochondrial biochemistry, serving to help catalyze reactions in numerous metalloenzymes.... (Review)
Review
Iron, copper, zinc, manganese, cobalt, and molybdenum play important roles in mitochondrial biochemistry, serving to help catalyze reactions in numerous metalloenzymes. These metals are also found in labile "pools" within mitochondria. Although the composition and cellular function of these pools are largely unknown, they are thought to be comprised of nonproteinaceous low-molecular-mass (LMM) metal complexes. Many problems must be solved before these pools can be fully defined, especially problems stemming from the lability of such complexes. This lability arises from inherently weak coordinate bonds between ligands and metals. This is an advantage for catalysis and trafficking, but it makes characterization difficult. The most popular strategy for investigating such pools is to detect them using chelator probes with fluorescent properties that change upon metal coordination. Characterization is limited because of the inevitable destruction of the complexes during their detection. Moreover, probes likely react with more than one type of metal complex, confusing analyses. An alternative approach is to use liquid chromatography (LC) coupled with inductively coupled plasma mass spectrometry (ICP-MS). With help from a previous lab member, the authors recently developed an LC-ICP-MS approach to analyze LMM extracts from yeast and mammalian mitochondria. They detected several metal complexes, including Fe580, Fe1100, Fe1500, Cu5000, Zn1200, Zn1500, Mn1100, Mn2000, Co1200, Co1500, and Mo780 (numbers refer to approximate masses in daltons). Many of these may be used to metalate apo-metalloproteins as they fold inside the organelle. The LC-based approach also has challenges, e.g., in distinguishing artifactual metal complexes from endogenous ones, due to the fact that cells must be disrupted to form extracts before they are passed through chromatography columns prior to analysis. Ultimately, both approaches will be needed to characterize these intriguing complexes and to elucidate their roles in mitochondrial biochemistry.
Topics: Animals; Chelating Agents; Chromatography, Liquid; Coordination Complexes; Fluorescent Dyes; Humans; Ligands; Mass Spectrometry; Metals; Mitochondria; Molecular Weight; Saccharomyces cerevisiae
PubMed: 27433847
DOI: 10.1021/acs.biochem.6b00216