Of the base and sugar

The temperature dependence of the chemical shifts of the base and sugar resonances of poly(dA-dT) in 0.1 M phosphate buffer is plotted in Figure 3. There are upfield and downfield shifts associated with the noncooperative premelting transition between 5 and 55°C while only downfield shifts are observed for most of the base and sugar protons on raising the temperature above 65°C in the noncooperative postmelting transition temperature range. 

Figure 8. The temperature dependence (5° to 95°C) of the base and sugar H-1 proton chemical shifts of polv(A-U) in 0.1 M phosphate, ImM EDTA, 2HtO,...

Figure 13. The temperature dependence of the base and sugar proton resonances of poly(dA-dT) in 1M NaCl, lOmM cacodylate solution (O), and in IM (2HtC),-NCI, lOmM phosphate solution (0). (2H C).NCI was purchased from Merck and used without further purification.

Figure 29. The temperature dependence of the base and sugar H-l resonances for poly(dA-dT) (O) and the daunomycin poly(dA-dT) complex, Nuc/D = 5 (9) in 1M NaCI, lOmM cacodylate, imM EDTA, 2H,0 solution...

The formation of an aldehyde group on a macromolecule can produce an extremely useful derivative for subsequent modification or conjugation reactions. In their native state, proteins, peptides, nucleic acids, and oligonucleotides contain no naturally occurring aldehyde residues. There are no aldehydes on amino acid side chains, none introduced by post-translational modifications, and no formyl groups on any of the bases or sugars of DNA and RNA. To create reactive aldehydes at specific locations within these molecules opens the possibility of directing modification reactions toward discrete sites within the macromolecule. 

NOESY in 2HzO provides the assignment of nonexchangeable base and sugar proton resonances, mostly through H6/8-H1 and H6/8-H2 /2" sequential connectivities. 

DNA is a polymer composed of monomeric nucleic acids called nucleotides. A nucleotide consists of a nitrogenous base, sugar, and phosphoric acid (whereas a nucleoside consists of only the base and sugar see Fig. A2.4). 

Fig. 12 Representation of the antibiofouling and sugar-specific recognition of a zwitterionic polymer-brush-based surface containing concanavalin A. Reprinted, with permission, from [171]. Copyright (2010) American Chemical Society...

The NMR resonances of the polynucleotide duplexes at the Watson-Crick protons, the base and sugar protons and the backbone phosphates would provide sufficient markers to monitor ligand-nucleic acid interactions in solution. Such an approach has great potential in adding to our current knowledge of the interactions... 

It should be noted that the products discussed within could also be formed via hydrogen atom addition. These hydrogen atoms can be generated via recombination of an electron and a proton or as products following excitation of the bases or sugar moiety. For exanqjle, in randomly oriented DNA a radical product was identified as being formed by radical addition to C8 in one of the purines (adenine or guanine) [78]. 

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