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Biochemistry. Biokhimiia Jul 2000The ligand properties of carnosine are analyzed. The stoichiometry, stability constants, and structural and spectroscopic characteristics of its coordination compounds... (Review)
Review
The ligand properties of carnosine are analyzed. The stoichiometry, stability constants, and structural and spectroscopic characteristics of its coordination compounds with transition and representative metal cations are discussed. Mixed ligand systems containing carnosine are also presented. The biological activity of some of these metallic complexes is briefly considered.
Topics: Carnosine; Ligands; Metals
PubMed: 10951097
DOI: No ID Found -
Biomolecules Nov 2020Transition metals interact with a large proportion of the proteome in all forms of life, and they play mandatory and irreplaceable roles. The dynamics of ligand binding... (Review)
Review
Transition metals interact with a large proportion of the proteome in all forms of life, and they play mandatory and irreplaceable roles. The dynamics of ligand binding to ions of transition metals falls within the realm of Coordination Chemistry, and it provides the basic principles controlling traffic, regulation, and use of metals in cells. Yet, the cellular environment stands out against the conditions prevailing in the test tube when studying metal ions and their interactions with various ligands. Indeed, the complex and often changing cellular environment stimulates fast metal-ligand exchange that mostly escapes presently available probing methods. Reducing the complexity of the problem with purified proteins or in model organisms, although useful, is not free from pitfalls and misleading results. These problems arise mainly from the absence of the biosynthetic machinery and accessory proteins or chaperones dealing with metal / metal groups in cells. Even cells struggle with metal selectivity, as they do not have a metal-directed quality control system for metalloproteins, and serendipitous metal binding is probably not exceptional. The issue of metal exchange in biology is reviewed with particular reference to iron and illustrating examples in patho-physiology, regulation, nutrition, and toxicity.
Topics: Animals; Binding Sites; Cell Physiological Phenomena; Humans; Metalloproteins; Metals; Protein Structure, Secondary
PubMed: 33233467
DOI: 10.3390/biom10111584 -
Microbiology (Reading, England) Mar 2010Microbes play key geoactive roles in the biosphere, particularly in the areas of element biotransformations and biogeochemical cycling, metal and mineral... (Review)
Review
Microbes play key geoactive roles in the biosphere, particularly in the areas of element biotransformations and biogeochemical cycling, metal and mineral transformations, decomposition, bioweathering, and soil and sediment formation. All kinds of microbes, including prokaryotes and eukaryotes and their symbiotic associations with each other and 'higher organisms', can contribute actively to geological phenomena, and central to many such geomicrobial processes are transformations of metals and minerals. Microbes have a variety of properties that can effect changes in metal speciation, toxicity and mobility, as well as mineral formation or mineral dissolution or deterioration. Such mechanisms are important components of natural biogeochemical cycles for metals as well as associated elements in biomass, soil, rocks and minerals, e.g. sulfur and phosphorus, and metalloids, actinides and metal radionuclides. Apart from being important in natural biosphere processes, metal and mineral transformations can have beneficial or detrimental consequences in a human context. Bioremediation is the application of biological systems to the clean-up of organic and inorganic pollution, with bacteria and fungi being the most important organisms for reclamation, immobilization or detoxification of metallic and radionuclide pollutants. Some biominerals or metallic elements deposited by microbes have catalytic and other properties in nanoparticle, crystalline or colloidal forms, and these are relevant to the development of novel biomaterials for technological and antimicrobial purposes. On the negative side, metal and mineral transformations by microbes may result in spoilage and destruction of natural and synthetic materials, rock and mineral-based building materials (e.g. concrete), acid mine drainage and associated metal pollution, biocorrosion of metals, alloys and related substances, and adverse effects on radionuclide speciation, mobility and containment, all with immense social and economic consequences. The ubiquity and importance of microbes in biosphere processes make geomicrobiology one of the most important concepts within microbiology, and one requiring an interdisciplinary approach to define environmental and applied significance and underpin exploitation in biotechnology.
Topics: Bacteria; Biodegradation, Environmental; Fungi; Geological Phenomena; Metals; Minerals; Soil Microbiology
PubMed: 20019082
DOI: 10.1099/mic.0.037143-0 -
Nucleic Acids Research Jul 2012In this article, we introduce BioMe (biologically relevant metals), a web-based platform for calculation of various statistical properties of metal-binding sites. Users...
In this article, we introduce BioMe (biologically relevant metals), a web-based platform for calculation of various statistical properties of metal-binding sites. Users can obtain the following statistical properties: presence of selected ligands in metal coordination sphere, distribution of coordination numbers, percentage of metal ions coordinated by the combination of selected ligands, distribution of monodentate and bidentate metal-carboxyl, bindings for ASP and GLU, percentage of particular binuclear metal centers, distribution of coordination geometry, descriptive statistics for a metal ion-donor distance and percentage of the selected metal ions coordinated by each of the selected ligands. Statistics is presented in numerical and graphical forms. The underlying database contains information about all contacts within the range of 3 Å from a metal ion found in the asymmetric crystal unit. The stored information for each metal ion includes Protein Data Bank code, structure determination method, types of metal-binding chains [protein, ribonucleic acid (RNA), deoxyribonucleic acid (DNA), water and other] and names of the bounded ligands (amino acid residue, RNA nucleotide, DNA nucleotide, water and other) and the coordination number, the coordination geometry and, if applicable, another metal(s). BioMe is on a regular weekly update schedule. It is accessible at http://metals.zesoi.fer.hr.
Topics: Binding Sites; DNA; Data Interpretation, Statistical; Internet; Ligands; Metalloproteins; Metals; RNA; Software; User-Computer Interface
PubMed: 22693222
DOI: 10.1093/nar/gks514 -
Metallomics : Integrated Biometal... Oct 2012How cells ensure correct metallation of a given protein and whether a degree of promiscuity in metal binding has evolved are largely unanswered questions. In a classic... (Review)
Review
How cells ensure correct metallation of a given protein and whether a degree of promiscuity in metal binding has evolved are largely unanswered questions. In a classic case, iron- and manganese-dependent superoxide dismutases (SODs) catalyze the disproportionation of superoxide using highly similar protein scaffolds and nearly identical active sites. However, most of these enzymes are active with only one metal, although both metals can bind in vitro and in vivo. Iron(ii) and manganese(ii) bind weakly to most proteins and possess similar coordination preferences. Their distinct redox properties suggest that they are unlikely to be interchangeable in biological systems except when they function in Lewis acid catalytic roles, yet recent work suggests this is not always the case. This review summarizes the diversity of ways in which iron and manganese are substituted in similar or identical protein frameworks. As models, we discuss (1) enzymes, such as epimerases, thought to use Fe(II) as a Lewis acid under normal growth conditions but which switch to Mn(II) under oxidative stress; (2) extradiol dioxygenases, which have been found to use both Fe(II) and Mn(II), the redox role of which in catalysis remains to be elucidated; (3) SODs, which use redox chemistry and are generally metal-specific; and (4) the class I ribonucleotide reductases (RNRs), which have evolved unique biosynthetic pathways to control metallation. The primary focus is the class Ib RNRs, which can catalyze formation of a stable radical on a tyrosine residue in their β2 subunits using either a di-iron or a recently characterized dimanganese cofactor. The physiological roles of enzymes that can switch between iron and manganese cofactors are discussed, as are insights obtained from the studies of many groups regarding iron and manganese homeostasis and the divergent and convergent strategies organisms use for control of protein metallation. We propose that, in many of the systems discussed, "discrimination" between metals is not performed by the protein itself, but it is instead determined by the environment in which the protein is expressed.
Topics: Bacterial Proteins; Binding Sites; Iron; Iron-Sulfur Proteins; Manganese; Metalloproteins; Models, Molecular; Nonheme Iron Proteins; Racemases and Epimerases; Ribonucleotide Reductases
PubMed: 22991063
DOI: 10.1039/c2mt20142a -
International Journal of Molecular... Aug 2020Carbonic anhydrases (CAs) and metallothioneins (MTs) are both families of zinc metalloproteins central to life, however, they coordinate and interact with their Zn ion... (Review)
Review
Carbonic anhydrases (CAs) and metallothioneins (MTs) are both families of zinc metalloproteins central to life, however, they coordinate and interact with their Zn ion cofactors in completely different ways. CAs and MTs are highly sensitive to the cellular environment and play key roles in maintaining cellular homeostasis. In addition, CAs and MTs have multiple isoforms with differentiated regulation. This review discusses current literature regarding these two families of metalloproteins in carcinogenesis, with a dialogue on the association of these two ubiquitous proteins in vitro in the context of metalation. Metalation of CA by Zn-MT and Cd-MT is described. Evidence for protein-protein interactions is introduced from changes in metalation profiles of MT from electrospray ionization mass spectrometry and the metalation rate from stopped-flow kinetics. The implications on cellular control of pH and metal donation is also discussed in the context of diseased states.
Topics: Animals; Cadmium; Carbonic Anhydrases; Humans; Metalloproteins; Metallothionein; Metals; Models, Molecular; Protein Binding; Protein Conformation; Spectrometry, Mass, Electrospray Ionization; Zinc
PubMed: 32784815
DOI: 10.3390/ijms21165697 -
Ecotoxicology and Environmental Safety Sep 2022Given the rapid development of nanotechnology, it is crucial to understand the effects of nanoparticles on living organisms. However, it is laborious to perform... (Review)
Review
Given the rapid development of nanotechnology, it is crucial to understand the effects of nanoparticles on living organisms. However, it is laborious to perform toxicological tests on a case-by-case basis. Quantitative structure-activity relationship (QSAR) is an effective computational technique because it saves time, costs, and animal sacrifice. Therefore, this review presents general procedures for the construction and application of nano-QSAR models of metal-based and metal-oxide nanoparticles (MBNPs and MONPs). We also provide an overview of available databases and common algorithms. The molecular descriptors and their roles in the toxicological interpretation of MBNPs and MONPs are systematically reviewed and the future of nano-QSAR is discussed. Finally, we address the growing demand for novel nano-specific descriptors, new computational strategies to address the data shortage, in situ data for regulatory concerns, a better understanding of the physicochemical properties of NPs with bioactivity, and, most importantly, the design of nano-QSAR for real-life environmental predictions rather than laboratory simulations.
Topics: Animals; Metal Nanoparticles; Metals; Nanotechnology; Oxides; Quantitative Structure-Activity Relationship
PubMed: 35961199
DOI: 10.1016/j.ecoenv.2022.113955 -
Annual Review of Physical Chemistry 2007Highly fluorescent, water-soluble, few-atom noble-metal quantum dots have been created that behave as multielectron artificial atoms with discrete, size-tunable... (Review)
Review
Highly fluorescent, water-soluble, few-atom noble-metal quantum dots have been created that behave as multielectron artificial atoms with discrete, size-tunable electronic transitions throughout the visible and near infrared. These molecular metals exhibit highly polarizable transitions and scale in size according to the simple relation E(Fermi)/N(1/3), predicted by the free-electron model of metallic behavior. This simple scaling indicates that fluorescence arises from intraband transitions of free electrons, and these conduction-electron transitions are the low-number limit of the plasmon-the collective dipole oscillations occurring when a continuous density of states is reached. Providing the missing link between atomic and nanoparticle behavior in noble metals, these emissive, water-soluble Au nanoclusters open new opportunities for biological labels, energy-transfer pairs, and light-emitting sources in nanoscale optoelectronics.
Topics: Fluorescent Dyes; Metals; Models, Chemical; Nanostructures; Photochemistry; Quantum Dots
PubMed: 17105412
DOI: 10.1146/annurev.physchem.58.032806.104546 -
BioMed Research International 2014Several workers have extensively worked out the metal induced toxicity and have reported the toxic and carcinogenic effects of metals in human and animals. It is well... (Review)
Review
Several workers have extensively worked out the metal induced toxicity and have reported the toxic and carcinogenic effects of metals in human and animals. It is well known that these metals play a crucial role in facilitating normal biological functions of cells as well. One of the major mechanisms associated with heavy metal toxicity has been attributed to generation of reactive oxygen and nitrogen species, which develops imbalance between the prooxidant elements and the antioxidants (reducing elements) in the body. In this process, a shift to the former is termed as oxidative stress. The oxidative stress mediated toxicity of heavy metals involves damage primarily to liver (hepatotoxicity), central nervous system (neurotoxicity), DNA (genotoxicity), and kidney (nephrotoxicity) in animals and humans. Heavy metals are reported to impact signaling cascade and associated factors leading to apoptosis. The present review illustrates an account of the current knowledge about the effects of heavy metals (mainly arsenic, lead, mercury, and cadmium) induced oxidative stress as well as the possible remedies of metal(s) toxicity through natural/synthetic antioxidants, which may render their effects by reducing the concentration of toxic metal(s). This paper primarily concerns the clinicopathological and biomedical implications of heavy metals induced oxidative stress and their toxicity management in mammals.
Topics: Animals; Antioxidants; Heavy Metal Poisoning; Humans; Metals, Heavy; Oxidation-Reduction; Oxidative Stress; Poisoning; Reactive Nitrogen Species; Reactive Oxygen Species
PubMed: 25184144
DOI: 10.1155/2014/640754 -
The Journal of Biological Chemistry Oct 2014Mononuclear iron enzymes can tightly bind non-activating metals. How do cells avoid mismetallation? The model bacterium Escherichia coli may control its metal pools so... (Review)
Review
Mononuclear iron enzymes can tightly bind non-activating metals. How do cells avoid mismetallation? The model bacterium Escherichia coli may control its metal pools so that thermodynamics favor the correct metallation of each enzyme. This system is disrupted, however, by superoxide and hydrogen peroxide. These species oxidize ferrous iron and thereby displace it from many iron-dependent mononuclear enzymes. Ultimately, zinc binds in its place, confers little activity, and imposes metabolic bottlenecks. Data suggest that E. coli compensates by using thiols to extract the zinc and by importing manganese to replace the catalytic iron atom. Manganese resists oxidants and provides substantial activity.
Topics: Cations, Divalent; Escherichia coli; Escherichia coli Proteins; Gene Expression; Hydrogen Peroxide; Iron; Manganese; Metalloproteins; Oxidation-Reduction; Oxidative Stress; Structure-Activity Relationship; Superoxides; Zinc
PubMed: 25160623
DOI: 10.1074/jbc.R114.588814