Astrid Sigel

Handbook on toxicity of inorganic compounds

This text consists of a total of 74 chapters of which 68 are devoted to individual elements and derived substances. The introductory chapter contains general definitions and describes the manner in which each elemental chapter is organized. For each of these chapters the points covered include chemistry and distribution, technological uses, physiological processes, detoxification mechanisms, levels of tolerance, summary of ecotoxicity, and analytical chemistry as well as a list of references. In addition to the elements, a chapter is also devoted to radiotoxicity. Aside from a discussion of individual elements, the second chapter covers the chemistry of inorganic compounds from the point of view of essentiality in biological systems and the properties and interdependency of these compounds. The third chapter is a very brief description of general principles used in toxicology, with emphasis on metals. The fourth chapter deals specifically with the collection, storage, and handling of biological materials for subsequent analysis. This is followed by chapters on the individual elements. The final chapter is a summary containing various tables describing values for threshold limits, biological tolerance, and acceptable intake.

Handbook on Metalloproteins

Interaction of sodium and potassium with proteins structure and function of sodium and potassium channel proteins in membranes magnesium-activated enzyme systems calcium and its enzymes vanadium in proteins and enzymes are there proteins containing chromium? manganese-containing enzymes and proteins iron in heme and related proteins iron-sulfur proteins structure-function of non-heme iron proteins with oxygen and nitrogen dominated coordination iron storage and transport cobalt in vitamin B12 and its enzymes nickel-containing enzymes copper proteins in the transport and activation of dioxygen, and the reduction of inorganic molecules multi-copper oxidases copper in electron transfer proteins proteins of various functions containing copper zinc sites in metalloenzymes and related proteins zinc finger proteins other zinc proteins -metallthioneins and insulin enzymes and proteins containing molybdenum or tungsten emerging themes and patterns among metalloproteins one and three letter symbols for the amino acids the standard genetic code.

Nickel and its surprising impact in nature

Volume 2 focuses on the vibrant research area concerning nickel as well as its complexes and their role in Nature. With more than 2800 references and over 130 illustrations, it is an essential resource for scientists working in the wide range from inorganic biochemistry all the way through to medicine. In 17 stimulating chapters, written by 47 internationally recognized experts, Nickel and Its Surprising Impact in Nature highlights critically the biogeochemistry of nickel, its role in the environment, in plants and cyanobacteria, as well as for the gastric pathogen Helicobacter pylori, for gene expression and carcinogenensis. In addition, it covers the complex-forming properties of nickel with amino acids, peptides, phosphates, nucleotides, and nucleic acids. The volume also provides sophisticated insights in the recent progress made in understanding the role of nickel in enzymes such as ureases, hydrogenases, superoxide dismutases, acireductone dioxygenases, acetyl-coenzyme A synthases, carbon monoxide dehydrogenases, methyl-coenzyme M reductases ... and it reveals the chaperones of nickel metabolism. The book opens with the biogeochemistry of this element and its release into the environment, which occurs from both natural and anthropogenic sources, whereby atmospheric distribution plays an important role. In the second chapter the impact of nickel on the metabolism of cyanobacteria and eukaryotic plants including deficiency and toxicity is considered, as is the application of nickel hyperaccumulator plants for phytomining and phytoremediation. Complex formation of nickel(II/III) with amino acids and peptides as well as of nickel(II) with sugar residues, nucleobases, phosphates, nucleosides, and nucleic acids is summarized in Chapters 3 and 4, respectively, by also taking into account intramolecular equilibria and comparisons with related metal ions. Bioinspired nickel coordination chemistry has flourished in recent years and the resulting synthetic models for the active sites of nickel-containing enzymes are reviewed in Chapter 5. In fact, each of the well established biological nickel sites is rather unique with respect to its structure and function. Hence, the following eight chapters are individually devoted to the various nickel enzymes which catalyze rather diverse reactions. For example, urease reduces the half life of urea in water from about 3.6 years to a few microseconds, whereas nickel-iron hydrogenases catalyze the heterolytic conversion of dihydrogen into protons and electrons and vice versa. Next, methyl-coenzyme M reductase and its nickel corphin coenzyme F430 in methanogenic archaea are described in detail as are acetyl-coenzyme A synthases and nickel-containing carbon monoxide dehydrogenases. These critical reviews are followed by in depth considerations on nickel superoxide dismutase, and the nickel-dependent glyoxalase I enzymes. The role of nickel in acireductone dioxygenase and the properties of the nickel-regulated peptidyl-prolyl cis/trans isomerase SlyD are discussed next. Nickel is toxic to cells and therefore the synthesis of nickel enzymes requires carefully controlled nickel-processing mechanisms that range from selective transport of nickel into the cells to productive insertion of nickel into the correct apoproteins. This demanding task is in the focus of Chapter 14 devoted to the chaperones of nickel metabolism. The primary colonization and long-term survival of Helicobacter pylori in the hostile gastric niche and the role of nickel in this environmental adaptation is covered in detail in Chapter 15. Nickel is widely employed in modern industry in conjunction with other metals for the production of alloys for coins, jewellery, and stainless steel; it is also used for plating, battery production, as a catalyst, etc. Workers are exposed to nickel at all stages of the processing of nickel-containing products through air, water or skin contacts. For example, the exposure to airborne nickel-containing particles has long been known to cause acute respiratory symptoms ranging from mild irritation and inflammation of the respiratory system to bronchitis, asthma, and pulmonary fibrosis and edema. Another well known adverse effect is allergic contact dermatitis. The indicated health problems caused by nickel exposure are mediated by an active change in the expression of genes that control inflammation, the response to stress, cell proliferation or cell death. All this and more is covered in Chapter 16. However, the most serious health effects beyond nickel toxicity relate to carcinogenesis; these concerns represent an area of considerable research activity today as is evident from the terminating chapter of Nickel and Its Surprising Impact in Nature.

Probing the Metal-Ion-Binding Strength of the Hydroxyl Group

Introduction How Is the Extent of a Weak Interaction Best Quantified? Metal-Ion Complexes with Phosph(on)ate Groups as Primary Binding Sites Extent of the Hydroxyl−M2+ Interaction in Complexes of Hydroxymethylphosphonate Metal-Ion−Glycerol 1-Phosphate Systems: A Decreasing Solvent Polarity Favors Hydroxyl−M2+ Interactions Some Generalizations Regarding Phosph(on)ate Ligands with a Weakly Coordinating Second Site Metal-Ion Complexes with Carboxylate Groups as Primary Binding Sites Extent of Chelate Formation in Complexes of Hydroxyacetate and Related Ligands at I = 0.1 M Construction of the Reference Lines for Several M2+−Carboxylate Systems. Extent of Chelate Formation in Metal-Ion Complexes Formed with Hydroxy Carboxylates and Related Ligands Extent of Chelate Formation in Complexes of Hydroxyacetate-Type Ligands at I = 2 M Effect of Chelate-Ring Enlargement on the Hydroxyl−Metal-Ion Interaction Decreasing Solvent Polarity Favors the Hydroxyl−Metal-Ion Interaction in Complexes of Hydroxyacetate and Related O Ligands But Inhibits Thioether Interactions Metal-Ion Complexes with Amino Groups as Primary Binding Sites Estimation of Straight-Line Parameters for Complexes Formed with RCH2−NH2 Ligands Extent of Hydroxyl Group−Metal-Ion Binding in Complexes of 2-Aminoethanol and Related Ligands Comparison of the Metal-Ion-Binding Properties of 2-Aminoethanol and Triethanolamine Imidazole Residue as a Primary Binding Site in Ligands Containing also a Hydroxyl Group Pyridyl Nitrogen Is an Ideal Primary Metal-Ion-Binding Site for a Hydroxyl−Metal-Ion Interaction Isomeric Quantification of Metal-Ion Binding with Ligands Offering Two Hydroxyl Groups Effect of the Primary Binding Site on the Extent of the Hydroxyl−Metal-Ion Interaction Extent of Hydroxyl−Metal-Ion Interactions in Complexes Having a Bidentate Primary Binding Site Metal-Ion Complexes of Ligands with Two or More Hydroxyl Groups and at Least Four Binding Sites Complexes of the Alkaline EarthIons with Bistris and Some Related Buffers: Reduced Solvent Polarity Favors Metal-Ion−Hydroxyl Group Interactions Complexes of Several 3d and Related Metal Ions with Bistris and Derivatives Quest for Selectivity in Metal-Ion Coordination Involving Hydroxyl Groups General Conclusions

Interplay between Metal Ions and Nucleic Acids

Interplay between Metal Ions and Nucleic AcidsThe preceding Volume 9, Structural and Catalytic Roles of Metal Ions in RNA , wasto a large part devoted to ribozymes, a vibrant but well defi ned research area. Thepresent volume, though related to the previous one, is of a much wider characterby describing phenomena that are generally due to the interrelations between metalions and nucleic acids, especially DNA. Yet it should be noted that the role of metalion-nucleic acid interactions in medication, tumor diagnosis, and anticancerresearch is not specifi cally considered because these topics were dealt with inVolumes 41 and 42 of our series Metal Ions in Biological Systems . Instead, Volume10 focuses in 12 chapters on modern developments encompassing the wide rangefrom G-quadruplexes via DNAzymes to peptide nucleic acids (PNAs), topics ofrelevance, e.g., for chemistry and nanotechnology, but also for molecular biologyand genetic diagnostics.The volume opens with two general chapters. The fi rst one provides an overviewon metal ion-nucleic acid interactions and their characterization in solution bydescribing the identifi cation of metal ion binding sites with chemical and biochemicalmethods, the application of NMR, etc. It deals with the determination of bindingconstants and the effects of anions and buffers on metal ion binding to nucleic acids.The corresponding interactions as seen in the solid state by crystal structure analysisare the topic of Chapter 2. Though the interactions of metal ions with nucleic acidsand their constituents have attracted much attention over more than fi ve decades, thereview focuses mainly on results obtained during the past 15 years leading to tableswith over 200 entries. This large body of information is classifi ed and discussed.

Metals Ions in Biological System : Volume 39: Molybdenum and Tungsten: Their Roles in Biological Processes:

The biogeochemistry of molybdenum and tungsten transport, homeostasis, regulation and binding of molybdate and tungstate to proteins molybdenum nitrogenases - a crystallographic and mechanistic view chemical dinitrogen fixation by molybdenum and tungsten complexes - insights from co-ordination chemistry biosynthesis of nitrogenase iron-molybdenum-cofactor from Azotobacter Vinelandii molybdenum enzymes containing the pyranopterin cofactor - an overview the molybdenum and tungsten cofactors - a crystallographic view models for the pyranopterin-containing molybdenum and tungsten cofactors biosynthesis and molecular biology of the molybdenum cofactor (moco) molybdenum in nitrate reductase and nitrate oxidoreductase.

Structural and catalytic roles of metal ions in RNA.

The discovery of ribozymes triggered a huge interest in the chemistry and biology of RNAs. Much of the recently made progress focusing on metal ions is addressed in Volume 9. This book, written by 28 internationally recognized experts, provides a most up-to-date view and it is thus of special relevance for colleagues teaching courses in biological inorganic chemistry and for researchers dealing, e.g., with nucleic acids, gene expression, and enzymology, but also for those in analytical and bioinorganic chemistry or biophysics. Structural and Catalytic Roles of Metal Ions in RNA describes metal ion-binding motives, methods to detect and characterize metal ion binding sites, and the role of metal ions in folding and catalysis. It deals with diffuse metal ion binding, RNA quadruplexes, the regulation of riboswitches, metal ions and ribozymes, including artificial ribozymes. The ribosome, ribozymes and redox cofactors, as well as the binding of kinetically inert metal ions to RNA are also considered.

Metal Ions in Biological Systems, Volume 35: Iron Transport and Storage Microorganisms, Plants, and Animals

Microorganisms, Plants, and Animals, offers a comprehensive and timely account of this fascinating topic by 35 distinguished international authorities. In 18 stimulating chapters, this volume highlights first the biological cycling of iron in oceans, followed by accounts of the transport of iron in microorganisms, fungi, and plants, the roles and properties of siderophores, and the regulation of iron transport and uptake in animals, plants, and microorganisms; it evaluates the structure and structure-function relationships of ferritins and considers their uptake, storage (mineralization), and release of iron; it examines transferrin and its receptor, the homeostasis of iron, especially in humans, and the effect of other metals on iron transport, and it terminates with a chapter about the challenge to create iron chelators for clinical use.

Extent of Intramolecular π‐Stacks in Aqueous Solution in Mixed‐Ligand Copper(II) Complexes Formed by Heteroaromatic Amines and Several 2‐Aminopurine Derivatives of the Antivirally Active Nucleotide Analog 9‐[2‐(Phosphonomethoxy)ethyl]adenine (PMEA)

The acidity constants of twofold protonated, antivirally active, acyclic nucleoside phosphonates (ANPs), H2(PE)±, where PE2−=9‐[2‐(phosphonomethoxy)ethyl]adenine (PMEA2−), 2‐amino‐9‐[2‐(phosphonomethoxy)ethyl]purine (PME2AP2−), 2,6‐diamino‐9‐[2‐(phosphonomethoxy)ethyl]purine (PMEDAP2−), or 2‐amino‐6‐(dimethylamino)‐9‐[2‐(phosphonomethoxy)ethyl]purine (PME(2A6DMAP)2−), as well as the stability constants of the corresponding ternary Cu(Arm)(H;PE)+ and Cu(Arm)(PE) complexes, where Arm=2,2′‐bipyridine (bpy) or 1,10‐phenanthroline (phen), are compared. The constants for the systems containing PE2−=PMEDAP2− and PME(2A6DMAP)2− have been determined now by potentiometric pH titrations in aqueous solution at I=0.1M (NaNO3) and 25°; the corresponding results for the other ANPs were taken from our earlier work. The basicity of the terminal phosphonate group is very similar for all the ANP2− species, whereas the addition of a second amino substituent at the pyrimidine ring of the purine moiety significantly increases the basicity of the N(1) site. Detailed stability‐constant comparisons reveal that, in the monoprotonated ternary Cu(Arm)(H;PE)+ complexes, the proton is at the phosphonate group, that the ether O‐atom of the CH2OCH2P(O)

Metal ions in toxicology : effects, interactions, interdependencies

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