Interaction with metal ions

Sites and thermodynamic quantities associated with proton and metal ion interaction with ribonucleic acid, deoxyribonucleic acid and their constituent bases, nucleosides and nucleotides. R. M. Izatt, J. J. Christensen and J. H. Rytting, Chem. Rev., 1971, 71, 439-481 (229). 

Metal ion interactions with nucleic acids and nucleic acid derivatives. L. G. Marzilli, Prog. Inorg. 

It is now almost 50 years since the structure of DNA was elucidated by Watson and Crick (1) (Fig. 1). Since then the double helix has become an icon for modern scientific achievement. With the rapid growth of molecular biology and the consequent success of the human genome project (2) we are now firmly in a post-genomic era. However, in spite of, or perhaps because of this, efforts to understand fundamental aspects of metal-ion interactions with DNA continue to be vigorously pursued. 

Fig. 2.7. Characteristic rate constants (s 1) for substitution of inner-sphere H20 of various aqua ions. Note The substitution rates of water in complexes ML(H20)m will also depend on the symmetry of the complex (adapted from Frey, C.M. and Stuehr, J. (1974). Kinetics of metal ion interactions with nucleotides and base free phosphates in H. Sigel (ed.), Metal ions in biological systems (Vol. 1). Marcel Dekker, New York, p. 69).

In aqueous solutions, metal ions interact with and are bound to H20 molecules. Thus, in such solutions, Ni2+ should more accurately be represented as the aquo-metal ion [Ni(H20)6]2+. Aquometal ions tend to be acidic, and have a tendency to hydrolyze ... 

In the simplest case in which the trivalent Fe-57 ions are completely incorporated into the cooperative antiferromagnetic system of the bulk substrate, the Fe-57 ions are expected to align parallel or antiparallel to the magnetic ions of the substrate in a similar manner as the ferric ions of the substrate. When the trivalent Fe-57 ions are on the surface, however, their magnetization is considered to be reduced to some extent due to reduction in the number of neighboring magnetic metal ions interacting with them. 

An electron spin can relax by coupling with a neighboring electron spin. Therefore, when a paramagnetic metal ion interacts with a second paramagnetic metal ion, the electron relaxation rates of the two metal ions may be dramatically affected. If Si and S2 are the two spins coupled by a scalar interaction, new spin levels will be established due to the interaction, with total S varying in unitary steps from Si — S2I to Si + S2. The energies of these spin levels are given by )... 

The most important point is that this procedure provides a reliable and effective way for dealing with metal ion interactions with nucleotides. By maintaining the free magnesium ion at a single fixed concentration, the experimenter avoids any chance of uncontrolled variation in the [MgATp2-]/[ATP -j ratio. 

In very dilute metal solutions where dissociation is considered complete, the alkali metal ion is considered to be a normal solvated ion, as in electrolytic solutions, and it is generally conceded that the large volume change is to be ascribed chiefly to the solvated electron. As the concentration is increased it is quite obvious from conductance and magnetic data that metal ions interact with electrons to form some sort of an ion pair and also that electrons couple to form spin-paired species. The manner in which these species form is not entirely clear, nor is their... 

To illustrate the type of structures that will arise when metal ions interact with organic compounds, three examples which reveal the basic details of metal ion coordination complexes, are given below ... 

Since the metal ions interact with the humate anions to form the complexes the dissociation of the humic acid should be taken into account ... 

Marzilli, Luigi G., Metal-ion Interactions with Nucleic Acids and Nucleic Acid... 

Michael J. Clarke is the program director for inorganic, bioinorganic and organometallic, chemistry at NSF and holds a permanent position as a professor of chemistry at Boston College. His research focus is on how unusual transition metal ions interact with biological systems. He has... 

It is now pertinent to consider more deeply the interaction of Ag with thiols. It has long been realized that heavy metal ions interact with cell membrane-associated enzymes [15, 36, 37, 85-105] such metals include mercury, silver, copper and lead. The thiol group derived from cysteine residues is essential for the activity of many enzymes [102] many metals and biocides interact with this essential group in some way. These include the following interactions with RSH [99, 102] ... 

How metal ions interact with light to produce coior... 

The chemical form of a metal that accumulates in the kidney may vary among the metals. However, the ionic form of a metal is normally much more potent as a nephrotoxicant than the elemental form. Once in the body, metal ions interact with numerous molecules (albumin, metal-binding proteins, glutathione, amino acids, etc.) and move around the body primarily as reversible complexes. Unfortunately, little information is available on the chemical form of most metals that actually enters proximal tubular cells and additional research is needed in this area. 

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