Nucleotides anionic

The synthesis of some dinucleoside phosphates has been achieved1680 by the reaction of 5 -chloro-5 -deoxynucleosides with nucleotide anions. In that work, the 5 -chloro-5 -deoxynucleosides were conveniently obtained by treatment of the corresponding 2, 3 -0-isopropylidene-nucleoside with thionyl chloride. 

Both types of protonated macrocycles were found to form stable and selective complexes with both inorganic [i.e., SO , Co(CN)6, and Fe(CN)h ] and organic (i.e. carboxylate and nucleotide) polyanions in aqueous solution in the neutral pH range. Since selectivity in these systems depends on electrostatic and geometric effects, modification of macrocyclic cavity shape and size should allow one to control the selectivity sequence (Dietrich et al.. 1981). The interactions of 53 and 54 in their less than fully protonated forms with carboxylate and nucleotide anions have been investigated recently (Hosseini and Lehn, 1988). 

Large cavity macrocycles with many amino functions in their protonated form are also able to bind inorganic (SO ", Fe(CN)6 ) or organic (carboxylate, nucleotide) anions <85ICAL9, 87IC3902>. Selectivity in these systems depends on electrostatic and geometric effects, so that the greater the extent of protonation, the more stable the complex. 

Table 2 Summary of the binding constants K (M for the interaction between Zn(113) and various nucleotide anions measured in a 1 9 mixture of CH3CN/TRIS HCl buffer (10mM pH = 7.4).

To conclude this chapter, we refer to a couple of examples regarding the use of polymers for molecular recognition and sensing of nucleotide anions, a topic that has received increasing attention in recent years. ... 

Recently, Leszczynski and coworkers (Bao et al. 2006 Gu et al. 2006) used theB3LYP/DZP-H-t method to study the 5/ -O5 and Cy -Oy bond cleavage in pyrimidine nucleotides anion radical in their adiabatic states. This work supported the mechanism suggested by Simons and coworkers (Barrios et al. 2002). An alternative mechanism using the concept of electron-induced proton transfer mechanism was proposed by Dabkowska et al. (2005) considering a cytosine nucleotide as a model of DNA for creating SSBs in DNA. In this model. 

Dowex 1-X2 0.6 0.65 Strongly basic anion exchanger with S-DVB matrix for separation of small peptides, nucleotides, and large metal complexes. Molecular weight exclusion is <2700. 

Nicotinamide is an essential part of two important coenzymes nicotinamide adenine dinucleotide (NAD ) and nicotinamide adenine dinucleotide phosphate (NADP ) (Figure 18.19). The reduced forms of these coenzymes are NADH and NADPH. The nieotinamide eoenzymes (also known as pyridine nucleotides) are electron carriers. They play vital roles in a variety of enzyme-catalyzed oxidation-reduction reactions. (NAD is an electron acceptor in oxidative (catabolic) pathways and NADPH is an electron donor in reductive (biosynthetic) pathways.) These reactions involve direct transfer of hydride anion either to NAD(P) or from NAD(P)H. The enzymes that facilitate such... 

A correlation of enhanced synthesis of polyamines with rapid growth or cell proliferation has been observed 21. From a physiological point of view, polyamines are implicated as regulators of cell proliferative activity 22). It is well known that polyamines, as protonated polycations, can bind with nucleotide and nucleic acid anions 23 241 to affect biochemical reactivities and stabilize tertiary structures 25,26). 

Diaz-De-Leon F. Klotz K.L. Lagrimini L.M (1993) Nucleotide sequence of the tobacco Nicotiana tabacum) anionic peroxidase gene / / Plant Physiol. V. 101. P. 1117-1118. 

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