Nucleic acid/metal complex interactions

The ability to calculate redox potentials has powerfid implications. For example, elecfrocatalytic reactions of metal complexes, such as Ru(bpy)3 +, with DNA nucleobases, such as guanine, provide a sensitive method for detection of nucleic acids on surfaces in electrochemical DNA chips (see Nucleic Acid-Metal Ion Interactions) In these reactions, voltammetric oxidation of Ru(bpy)3 + to Ru(bpy)3 + in the presence of guanine produces an enhancement in the oxidative current due to the reaction of Ru(III) with guanine (Figure 2). On surfaces, the extent of elecfrocatalytic enhancement is indicative of the quantity of bound nucleic acid levels of DNA as low as 40 attomoles have been detected using related methods. ... 

Carbene Complexes Carbonyl Complexes ofthe Transition Metals Cyanide Complexes of the Transition Metals Dinuclear Organometallic Cluster Complexes Electron Transfer in Coordination Compounds Electron Transfer Reactions Theory Electronic Structure of Organometallic Compounds Luminescence Nucleic Acid-Metal Ion Interactions Photochemistry of Transition Metal Complexes Photochemistry of Transition Metal Complexes Theory Polynuclear Organometallic Cluster Complexes. 

Apart from the understanding of the mechanism of anti-tumour action of cis-[PtCl2(NH3)2l a major interest in the area of nucleic acid-metal ion interactions is the possibility of sequence determination, using specific binding of metal complexes. 

The ability to calculate redox potentials has powerful implications. For example, electrocatalytic reactions of metal complexes, such as Ru(bpy)3 +, with DNA nucleobases, such as guanine, provide a sensitive method for detection of nucleic acids on surfaces in electrochemical DNA chips see Nucleic Acid-Metal Ion Interaction In these reactions. 

Hsiao C, Tannenbaum E, VanDaeusen H, Hershkovitz E, Pemg G, Tannenbaum AR, Williams LD. Complexes of nucleic acids with group I and II cations. In HudNV, Editor. Nucleic acid-metal ion interactions. Cambridge Royal Society of Chemistry 2009. pp 1-38. Permyakov EA. Metalloproteins. New Jersey Wiley 1009. 

The influence of DNA on the photo-electron transfer process between a variety of donor-acceptor couples has been examined during the last ten years. For all the systems studied, the metal complex interacts with the DNA and plays the role of electron acceptor or donor in the hydrophobic DNA microenvironment, whereas the other partner of the process, i.e. the reducing or oxidising agent in the ground state, is localised either on the DNA double helix, or does not interact with the nucleic acid and remains in the aqueous phase. Thus three... 

X-ray crystallographic analyses usually provide structural information that correctly represents the actual structures of metal ion-nucleic acid complexes in the crystal this usually represents an environment that is drastically different from normal solution conditions. Obviously, such analyses are limited to complexes that are both stable and amenable to crystallization. In comparison, solution NMR spectroscopy data are much more generally applicable to the analysis of metal ion-nucleic acid structure, " " but can be more easily misinterpreted owing to factors such as the distribution of metal ions among several binding sites and the intrinsically weaker nature of some of the interactions that are studied. Also, nucleic acid crystallization requires the formation of ordered and uniform intermolecular interactions between nucleic acids. These intermolecular interactions may either compete or interfere with the formation of certain metal-nucleic complexes and promote the formation of unnatural metal binding centers. ... 

Although many studies on DNA and DNA-protein interaction have utilized metal shadowing to produce bright-held image contrast, dark-held TEM (annular or spectroscopic) of unstained or uranyl acetate-stained and metal-shadowed nucleic acid-protein complexes also provides useful resolution. In Figure 5, a short length of DNA (2356 base pairs), with attached progesterone receptor, is revealed by dark-held TEM. The RecA protein has the ability to... 

Metal ions, small organic molecules, peptides and small proteins are the ligands tested thus far. PLIMSTEX should be applicable to other ligands including nucleic acids and other proteins. PLIMSTEX should have utility for measuring affinities of proteins in complexes as well as alone, and if this works, it may be one of the few techniques that can probe interaction of a ligand with one protein that is interacting with others. 

Metal NPs were also used as labels to follow aptamer-substrate interactions. The supramolecular self-organization of the aptamer-substrate complexes on surfaces was implemented to develop different configurations of electrical aptasensors.88 The anticocaine aptamer was separated into two fragments (37 and 38) (Fig. 12.24a). The nucleic acid (37) was assembled on a Au electrode, whereas the nucleic acid (38) was... 

Heavier metal ions and metal complexes can find sites on nitrogen atoms of the nucleic acid bases. Examples are the platinum complex cisplatin and the DNA-cleaving antibiotic neocarzinostatin (Box 5-B). Can metals interact with the n electrons of stacked DNA bases A surprising result has been reported for intercalating complexes of ruthenium (Ru) and rhodium (Rh). Apparent transfer of electrons between Ru (II) and Rh (III) over distances in excess of 4.0 nm, presumably through the stacked bases, has been observed,181 as has electron transfer from other ions.181a Stacked bases are apparently semiconductors.182... 

The foundation of metal ion and nucleic acid interactions as a chemotherapy originate with the well known work of Rosenberg64 on platinum(II) complexes. Those containing chelating agents could destabilize nucleic acid structures by removing cations which promote the stability of histones. 

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