Influence of DNA Acidification on DNA Premelting and Template Properties

Sarocchi, Marie-Thérèse; Dausse, Jean‐Pierre; Guschlbauer, Wilhelm

doi:10.1111/j.1432-1033.1976.tb10376.x

Cited by 5 publications

(2 citation statements)

References 55 publications

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“…Many other articles have been published dealing with the protonation of different polynucleotides, and for almost all studies C‐containing sequences have been selected, since this base is generally considered the preferred site of protonation 14–24…”

Section: Introductionmentioning

confidence: 99%

Titration of poly(dA‐dT) · poly(dA‐dT) in solution at variable NaCl concentration

et al. 2004

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CD and uv absorption data showed that high molecular weight poly(dA-dT) . poly(dA-dT), at 298 K, undergoes an acid-induced transition from B-double helix to random coil in NaCl solutions of different concentrations, ranging from 0.005 to 0.600M. Similarly, titration of the polynucleotide with a strong base causes duplex-to-single strands transition. The base- and acid-induced transitions were both reversible by back-titration (with an acid or, respectively, with a base): the apparent pKa were the same in both directions. However, the number of protons per titratable site (adenine N1) required to reach half-denaturation was in great excess over the stoichiometric value; to a much larger extent, the same effect was observed also for the deprotonation of the N3H sites of thymine. Moreover, in the basic denaturation experiments, at low salt concentrations ([NaCl]< or =0.300M) less acid than calculated was needed to back-titrate the base excess to half-denaturation. Both effects could be qualitatively justified on the basis of the counterion condensation theory of polyelectrolytes and considering the energy barrier created by the negatively charged phosphodiester groups to the penetration of the OH- ions inside the double helix and the screening effect of the Na+ ions on such charges, in the deprotonation experiments.

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Section: Introductionmentioning

confidence: 99%

Titration of poly(dA‐dT) · poly(dA‐dT) in solution at variable NaCl concentration

et al. 2004

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“…Indeed, a variety of conformations of DNA sequences has been observed as a result of protonation in water solution 1 and a considerable amount of reports can be found on this subject. [2][3][4][5][6][7][8][9][10][11][12][13][14][15] On the other hand, only a limited number of publications addresses the problem of alkaline titrations of DNA models in solution. [16][17][18][19][20] Investigations on the responses of DNA to pH variations, when it is confined in aqueous compartments of limited volume, would seem at least as interesting as the solution studies, since in cells DNA is restricted in regions of limited dimensions compared to its length.…”

Section: Introductionmentioning

confidence: 99%

PolyAT chemical denaturation in w/o microemulsion

Airoldi¹,

Boicelli²,

Cadoni³

et al. 2004

Phys. Chem. Chem. Phys.

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CD and UV spectroscopies have been used to investigate the effects caused by the addition of either strong acid-or base-containing microemulsions on the behaviour of the synthetic polynucleotide polyAT entrapped in the aqueous core of a cationic quaternary water-in-oil microemulsion (μE). The titrations were performed in the presence of variable concentrations of NaCl, in the range 0.00 to 0.60 M. In both cases, the primary effect was the reversible transition from B-double helix to random coil of the guest polynucleotide. However, in the microemulsive medium, the number of moles of protons (RH) and hydroxide ions (ROH) per mole of titrable sites are independent of the salt concentration but larger than 0.5, the value predicted on the basis of the stoicheiometry of the protonation-deprotonation processes. This result is in contrast with that obtained in aqueous solution (higher RH and ROH values and strongly dependent on NaCl concentration) and is explained with the presence of the cationic micellar wall (CTAB polar heads) acting as a ionic strength buffer

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CD spectra of isoionic DNA solutions

Давыдова

Кузнецов

Florentiev³

1989

Biopolymers

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The ion-exchange transition of Na-DNA----H-DNA in concentrated salt-free solutions is accompanied by strong variations in CD spectra. The rotational force of the negative band magnitude of delta epsilon 249 decreases when going to H-DNA by about 4 times, and the value of delta epsilon 279, by 1.2 times. These changes are irreversible to a considerable extent, which is evident because the spectra of Na-DNA obtained by neutralizing isoionic H-DNA solutions with NaOH or by the ion-exchange method significantly differ from those of Na-DNA taken by dissolving solid Na-DNA in deionized water. It has been shown that additions of NaCl to an isoionic solution of DNA leads to variations of spectra, typical for deprotonation processes as well as for an increase in DNA hydration.

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Influence of DNA Acidification on DNA Premelting and Template Properties

Cited by 5 publications

References 55 publications

Titration of poly(dA‐dT) · poly(dA‐dT) in solution at variable NaCl concentration

Titration of poly(dA‐dT) · poly(dA‐dT) in solution at variable NaCl concentration

PolyAT chemical denaturation in w/o microemulsion

CD spectra of isoionic DNA solutions

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