Nucleotides dinucleotides

Zorbax ODSS (10 pm), Nucleosil ODSS (5 pm) Octadecylsulfonated silica(ODSS) Separation of nucleotides, dinucleotides, transfer-ribonucleic acids MeCN-aqueous phosphate 35 65 v/v, 9.75 mM phosphate, 3.25 mM tetrabutyl ammonium bromide, pH 6.50 MeCN-MeOH-12mM ammonium phosphate30 40 30, v/v/v, pH 6.0 [93]... 

Dideoxy-adenosine, -inosine, and -cytidine have been determined in biological samples by both reversed-phase and ion-pair reversed-phase methods. An ion-pair (Bu" N ) reversed-phase analysis of purine nucleosides, bases, nucleotides, dinucleotides, and nucleoside derivatives (adenosyl-homocysteine, -succinate, and -methionine) from acid-extracted tissues was undertaken to investigate adenosine reservoirs in rats on treatment with a metabolic inhibitor which blocks adenosine transport. 

Coemymes effecting transfer of hydrogen. These include the pyridine nucleotides, nicotinamide-adenine dinucleolide and nicotinamide-adenine dinucleolide phosphate the flavin nucleotides such as flavin-adenine dinucleotide and lipoic acid. 

Flavin adenine dinucleotide (FAD) has been electropolymerized using cyclic voltammetry. Cyclic voltammograms of poly (FAD) modified electrode were demonstrated dramatic anodic current increasing when the electrolyte solution contained NADH compare with the absence of pyridine nucleotide. 

P-Nicotinamide adenine dinucleotide reduced di-Na salt trihydrate (reduced diphosphopyridine nucleotide sodium salt, NADH) [606-68-8] M 763.5, pK as for NAD. 

Nicotinamide adenine dinucleotide phosphate reduced tetrasodium salt (reduced diphosphopyridine nucleotide phosphate sodium salt, NADPH) [2646-71-1] M 833.4, pK as for NADP. Mostly similar to NADH above. 

Because alternate nucleotides assume different conformations, the repeating unit on a given strand in the Z-helix is the dinucleotide. That is, for any number of bases, n, along one strand, n — dinucleotides must be considered. For example, a GpCpGpC subset of sequence along one strand is comprised... 

Several classes of vitamins are related to, or are precursors of, coenzymes that contain adenine nucleotides as part of their structure. These coenzymes include the flavin dinucleotides, the pyridine dinucleotides, and coenzyme A. The adenine nucleotide portion of these coenzymes does not participate actively in the reactions of these coenzymes rather, it enables the proper enzymes to recognize the coenzyme. Specifically, the adenine nucleotide greatly increases both the affinity and the speeifieity of the coenzyme for its site on the enzyme, owing to its numerous sites for hydrogen bonding, and also the hydrophobic and ionic bonding possibilities it brings to the coenzyme structure. 

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... 

Methylthiomethyl Nicotinamide adenine dinucleotide Sodium triphosphopyridine nucleotide Napthyl (CioHg)... 

The 5 -phosphoryl group of a mononucleotide can es-terify a second —OH group, forming a phosphodi-ester. Most commonly, this second —OH group is the 3 -OH of the pentose of a second nucleotide. This forms a dinucleotide in which the pentose moieties are linked by a 3 —> 5 phosphodiester bond to form the backbone of RNA and DNA. 

Trinucleotides are formed by 5 -deprotection of the dinucleotide and subsequent conversion with the monotriazolide in the presence of N-methylimidazole. The fully protected di- and trideoxyribonucleotides of the following nucleotide sequences have been obtained in high yield T-T (82%), C-T (88%), C-C (84%), CM3 (81%), G-T (83%), A-G-T (65%), C-G-T (61%). The yields are similar to those obtained in a reaction involving l-(triisopropylbenzenesulfonyl)tetrazole as coupling agent(see also Section 12.7). 

Fig. 6.16 Comparison of phosphate and glyoxylate chemical structures, and their associated nucleotides and dinucleotides (From H.D. Bean et al., 2006)...

Curnutte, J. T. (1985). Activation of human neutrophil nicotinamide adenine dinucleotide phosphate, reduced (triphosphopyridine nucleotide, reduced) oxidase by arachidonic acid in a cell-free system. J. Clin. Invest. 75, 1740-3. 

Additional steps occur in the case of eubacteria, namely syntheses of various dinucleotide forms of the cofactor, in which the pyranopterin is linked to a second nucleotide via a pyrophosphate linkage [34]. 

Autofluorescence of cells often complicates the studies with fluorescence microscopy (especially the application of green fluorescent substances). There are different reasons for the occurrence of this phenomenon (157) (i) the fluorescent pigment lipofuscin, which settles with rising age in the cytoplasm of cells (ii) cell culture medium, which often contains phenol red that increases autofluorescence (iii) endogen substances such as flavin coenzymes [flavin-adenine dinucleotide (FDA), flavin mononucleotide (FMN) absorp-tion/emission 450/515nm], pyridine nucleotides [reduced nicotinamide adenine dinucleotide (NADH) absorption/emission 340/460nm] or porphyrine (iv) substances taken up by cells (as mentioned above filipin) and (v) preparation of the cells fixation with glutaraldehyde increases autofluorescence. 

---