Read by QxMD icon Read

Metal Ions in Life Sciences

Astrid Sigel, Helmut Sigel, Roland K O Sigel
No abstract text is available yet for this article.
2016: Metal Ions in Life Sciences
Yonghwang Ha, Jeong A Jeong, Youngsam Kim, David G Churchill
Alkali metals, especially sodium and potassium, are plentiful and vital in biological systems. They take on important roles in health and disease. Such roles include the regulation of homeostasis, osmosis, blood pressure, electrolytic equilibria, and electric current. However, there is a limit to our present understanding; the ions have a great ability and capacity for action in health and disease, much greater than our current understanding. For the regulation of physiological homeostasis, there is a crucial regulator (renin-angiotensin system, RAS), found at both peripheral and central levels...
2016: Metal Ions in Life Sciences
Duarte Mota de Freitas, Brian D Leverson, Jesse L Goossens
In this chapter, we review the mechanism of action of lithium salts from a chemical perspective. A description on how lithium salts are used to treat mental illnesses, in particular bipolar disorder, and other disease states is provided. Emphasis is not placed on the genetics and the psychopharmacology of the ailments for which lithium salts have proven to be beneficial. Rather we highlight the application of chemical methodologies for the characterization of the cellular targets of lithium salts and their distribution in tissues...
2016: Metal Ions in Life Sciences
Nuria Rodríguez-Vázquez, Alberto Fuertes, Manuel Amorín, Juan R Granja
In Nature, all biological systems present a high level of compartmentalization in order to carry out a wide variety of functions in a very specific way. Hence, they need ways to be connected with the environment for communication, homeostasis equilibrium, nutrition, waste elimination, etc. The biological membranes carry out these functions; they consist of physical insulating barriers constituted mainly by phospholipids. These amphipathic molecules spontaneously aggregate in water to form bilayers in which the polar groups are exposed to the aqueous media while the non-polar chains self-organize by aggregating to each other to stay away from the aqueous media...
2016: Metal Ions in Life Sciences
Hideki Sakai, Takuto Fujii, Noriaki Takeguchi
As a physiological phenomenon, acid secretion from the stomach was known already at least in the 17th century. But its mechanism was elucidated in more recent times only. At the end of the 20th century, gastric H(+)/K(+)-ATPase in the parietal cells was found to be responsible for a final step of H(+) secretion in these cells. In this century, several Cl(-)-transporting proteins for gastric acid (hydrochloric acid; HCl) secretion have been found. As inhibitors of gastric acid secretion, histamine H2 receptor antagonists (H2 blockers) were developed in the 1970's...
2016: Metal Ions in Life Sciences
Etana Padan, Meytal Landau
The transmembranal Na(+)/H(+) antiporters transport sodium (or several other monovalent cations) in exchange for H(+) across lipid bilayers in all kingdoms of life. They are critical in pH homeostasis of the cytoplasm and/or organelles. A particularly notable example is the SLC9 gene family, which encodes Na(+)/H(+) exchangers (NHEs) in many species from prokaryotes to eukaryotes. In humans, these proteins are associated with the pathophysiology of various diseases. Yet, the most extensively studied Na(+)/H(+) antiporter is Ec-NhaA, the main Na(+)/H(+) antiporter of Escherichia coli...
2016: Metal Ions in Life Sciences
Günter Fritz, Julia Steuber
Among the alkali cations, Na(+) has an extraordinary role in living cells since it is used to charge the battery of life. To this end, sophisticated protein complexes in biological membranes convert chemical energy obtained from oxidation of NADH, or hydrolysis of ATP, into an electrochemical gradient of sodium ions. Cells use this so-called sodium-motive force stored in energy-converting membranes for important processes like uptake of nutrients, motility, or expulsion of toxic compounds. The Na(+) pumps act in concert with other enzymes embedded in the lipid membrane, and together they form the respiratory chain which achieves the oxidation of NADH derived from nutrients under formation of an electrochemical sodium (or proton) gradient...
2016: Metal Ions in Life Sciences
Carmay Lim, Todor Dudev
Transport of Na(+) and K(+) ions across the cell membrane is carried out by specialized pore-forming ion channel proteins, which exert tight control on electrical signals in cells by regulating the inward/outward flow of the respective cation. As Na(+) and K(+) ions are both present in the body fluids, their respective ion channels should discriminate with high fidelity between the two competing metal ions, conducting the native cation while rejecting its monovalent contender (and other ions present in the cellular/extracellular milieu)...
2016: Metal Ions in Life Sciences
Manuel Nieves-Cordones, Fouad Razzaq Al Shiblawi, Hervé Sentenac
The two alkali cations Na(+) and K(+) have similar relative abundances in the earth crust but display very different distributions in the biosphere. In all living organisms, K(+) is the major inorganic cation in the cytoplasm, where its concentration (ca. 0.1 M) is usually several times higher than that of Na(+). Accumulation of Na(+) at high concentrations in the cytoplasm results in deleterious effects on cell metabolism, e.g., on photosynthetic activity in plants. Thus, Na(+) is compartmentalized outside the cytoplasm...
2016: Metal Ions in Life Sciences
Milan Vašák, Joachim Schnabl
The group I alkali metal ions Na(+) and K(+) are ubiquitous components of biological fluids that surround biological macromolecules. They play important roles other than being nonspecific ionic buffering agents or mediators of solute exchange and transport. Molecular evolution and regulated high intracellular and extracellular M(+) concentrations led to incorporation of selective Na(+) and K(+) binding sites into enzymes to stabilize catalytic intermediates or to provide optimal positioning of substrates. The mechanism of M(+) activation, as derived from kinetic studies along with structural analysis, has led to the classification of cofactor-like (type I) or allosteric effector (type II) activated enzymes...
2016: Metal Ions in Life Sciences
Eric Largy, Jean-Louis Mergny, Valérie Gabelica
G-quadruplexes are guanine-rich nucleic acids that fold by forming successive quartets of guanines (the G-tetrads), stabilized by intra-quartet hydrogen bonds, inter-quartet stacking, and cation coordination. This specific although highly polymorphic type of secondary structure deviates significantly from the classical B-DNA duplex. G-quadruplexes are detectable in human cells and are strongly suspected to be involved in a number of biological processes at the DNA and RNA levels. The vast structural polymorphism exhibited by G-quadruplexes, together with their putative biological relevance, makes them attractive therapeutic targets compared to canonical duplex DNA...
2016: Metal Ions in Life Sciences
Pascal Auffinger, Luigi D'Ascenzo, Eric Ennifar
Metal ions are essential cofactors for the structure and functions of nucleic acids. Yet, the early discovery in the 70s of the crucial role of Mg(2+) in stabilizing tRNA structures has occulted for a long time the importance of monovalent cations. Renewed interest in these ions was brought in the late 90s by the discovery of specific potassium metal ions in the core of a group I intron. Their importance in nucleic acid folding and catalytic activity is now well established. However, detection of K(+) and Na(+) ions is notoriously problematic and the question about their specificity is recurrent...
2016: Metal Ions in Life Sciences
Francesco Crea, Concetta De Stefano, Claudia Foti, Gabriele Lando, Demetrio Milea, Silvio Sammartano
Alkali metal ions play very important roles in all biological systems, some of them are essential for life. Their concentration depends on several physiological factors and is very variable. For example, sodium concentrations in human fluids vary from quite low (e.g., 8.2 mmol dm(-3) in mature maternal milk) to high values (0.14 mol dm(-3) in blood plasma). While many data on the concentration of Na(+) and K(+) in various fluids are available, the information on other alkali metal cations is scarce. Since many vital functions depend on the network of interactions occurring in various biofluids, this chapter reviews their complex formation with phosphates, nucleotides, amino acids, and related ligands of biological relevance...
2016: Metal Ions in Life Sciences
Mary T Rodgers, Peter B Armentrout
Quantitative insight into the structures and thermodynamics of alkali metal cations interacting with biological molecules can be obtained from studies in the gas phase combined with theoretical work. In this chapter, the fundamentals of the experimental and theoretical techniques are first summarized and results for such work on complexes of alkali metal cations with amino acids, small peptides, and nucleobases are reviewed. Periodic trends in how these interactions vary as the alkali metal cations get heavier are highlighted...
2016: Metal Ions in Life Sciences
Katsuyuki Aoki, Kazutaka Murayama, Ning-Hai Hu
This chapter provides structural data, mainly metal binding sites/modes, observed in crystal structures of alkali metal ion complexes containing low-molecular-weight ligands of biological relevance, mostly obtained from the Cambridge Structural Database (the CSD version 5.35 updated to February 2014). These ligands include (i) amino acids and small peptides, (ii) nucleic acid constituents (excluding quadruplexes and other oligonucleotides), (iii) simple carbohydrates, and (iv) naturally occurring antibiotic ionophores...
2016: Metal Ions in Life Sciences
Peter C Hauser
An overview of the common methods for the determination of the alkali metals is given. These are drawn from all of the three principle branches of quantitative analysis and consist mainly of optical atomic spectrometric methods, ion-selective electrodes, and the separation methods of ion-chromatography and capillary electrophoresis. Their main characteristics and performance parameters are discussed. Important specific applications are also examined, namely clinical analysis, single cell analysis, the analysis of soil samples and hydroponic nutrient solutions, as well as the detection of the radioactive (137)Cs isotope...
2016: Metal Ions in Life Sciences
Youngsam Kim, Thuy-Tien T Nguyen, David G Churchill
The common Group 1 alkali metals are indeed ubiquitous on earth, in the oceans and in biological systems. In this introductory chapter, concepts involving aqueous chemistry and aspects of general coordination chemistry and oxygen atom donor chemistry are introduced. Also, there are nuclear isotopes of importance. A general discussion of Group 1 begins from the prevalence of the ions, and from a comparison of their ionic radii and ionization energies. While oxygen and water molecule binding have the most relevance to biology and in forming a detailed understanding between the elements, there is a wide range of basic chemistry that is potentially important, especially with respect to biological chelation and synthetic multi-dentate ligand design...
2016: Metal Ions in Life Sciences
Peter M H Kroneck, Martha E Sosa Torres
No abstract text is available yet for this article.
2015: Metal Ions in Life Sciences
Astrid Sigel, Helmut Sigel, Roland K O Sigel
No abstract text is available yet for this article.
2015: Metal Ions in Life Sciences
Joachim Reimann, Mike S M Jetten, Jan T Keltjens
Ammonium and methane are inert molecules and dedicated enzymes are required to break up the N-H and C-H bonds. Until recently, only aerobic microorganisms were known to grow by the oxidation of ammonium or methane. Apart from respiration, oxygen was specifically utilized to activate the inert substrates. The presumed obligatory need for oxygen may have resisted the search for microorganisms that are capable of the anaerobic oxidation of ammonium and of methane. However extremely slowly growing, these "impossible" organisms exist and they found other means to tackle ammonium and methane...
2015: Metal Ions in Life Sciences
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"