Journal ArticleDOI
The electrochemical behaviour of DNA at electrically charged interfaces.
P. Valenta,H. W. Nürnberg +1 more
- Vol. 1, Iss: 1, pp 17-26
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TLDR
The adsorption and the reduction of native and denatured DNA has been studied at the hanging mercury drop electrode by triangular sweep polarography and the results have with respect to the physicochemical properties of DNA general significance also for the behaviour of nucleic acids at charged biological interfaces.Abstract:
The adsorption and the reduction of native and denatured DNA has been studied at the hanging mercury drop electrode (HMDE) by triangular sweep polarography. It has been established from the dependence of the reduction peak of denatured DNA (Fig. 2) on the waiting time at the starting potential E8 of the sweep (Fig. 3) where the adsorption takes place and on pH (Fig. 4) that a protonated form of denatured DNA is reduced from the adsorbed state in a totally irreversible electrode process at a pH lower than 7.5. From the logarithmic analysis of the beginning part of the reduction peak the charge transfer rate constant and the charge transfer coefficient were determined (Fig. 5). The reduction products are interconnected to a high molecular network strongly adhering to the surface of the electrode and blocking it for a repeated reduction on the same drop. In neutral media the protonation of DNA becomes rate-determining. The adsorption is diffusion controlled and from the time dependence of the coverage the diffusion coefficient of DNA could be estimated (Fig. 6) to 5.10−7 cm2 s−1 in 1 M KCl at 25 ‡C and at pH 6.7 for denatured DNA of the mean molecular weight 106 g. The protonated molecules of DNA are adsorbed via strong induced dipole interactions of theπ-electron system in the heteroaromatic ring of the bases with electrons of the metal while the other parts of the DNA molecule including the solvated sugar and phosphate groups are orientated to the solution. From the time integral of the reduction peak (Fig. 6) the maximal surface concentration of the electrochemically active monomeric units in DNA was estimated to 1.4·10−10 mol cm−2 with an average area per mononucleotide of about 60 a2. Both values vary only within 10% in the temperature range 5 to 25 ‡C, in the concentration range of DNA 10 to 360 Μg/ml and for starting potentials Es −0.2 to −1.3 V vs. SCE. Native DNA is also adsorbed at the electrode and reduced in acid solutions in the same irreversible electrode reaction as denatured DNA. However, before a partial opening of the helix is induced by the strong electric field at the interface leading with respect to helix-coil transition to an effect equivalent to partial melting which has to precede the electron transfer step. The extent of unscreened reducible groups and their orientation with the electrochemically reactive sites towards the electrode depends on pH (Fig. 8), on electrical parameters of the interface as the starting potential Es (Fig. 7) and on the portion of the DNA molecule which comes into the region where the electric field is acting. The maximal extents of unscreened reducible groups are 85% for native DNA of the mean molecular weight of 2.5·106 g and 46% for native DNA of the mean molecular weight 107 g (Fig. 6). The results have with respect to the physicochemical properties of DNA general significance also for the behaviour of nucleic acids at charged biological interfaces as for instance the membrane of living cells.read more
Citations
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Journal ArticleDOI
Electrochemistry of nucleic acids.
Emil Paleček,Martin Bartošík +1 more
TL;DR: Oscillographic polarography, at controlled alternating current, was used in the electrochemical analysis of nucleic acids and briefly summarizes some properties of the elimination voltammetry with linear scan (EVLS) method.
Journal ArticleDOI
SERS-melting: a new method for discriminating mutations in DNA sequences.
TL;DR: A novel method that uses surface enhanced (resonance) Raman spectroscopy (SER(R)S) to follow denaturation of dsDNA attached to a structured gold surface that has the potential to provide small, rapid, sensitive, reproducible platforms for detecting genetic variations and sequencing genes.
Book ChapterDOI
Surface enhanced raman scattering of biomolecules
TL;DR: A review of SERS and SERRS from biomolecules adsorbed on a metal surface is given in this article, where the technical aspects of the instrumentation and procedure as also the fundamentals of the SERS theory are exposed.
Book ChapterDOI
Electrochemistry of Nucleic Acids
Emil Paleček,František Jelen +1 more
TL;DR: Oscillographic polarography, at controlled alternating current, was used in the electrochemical analysis of nucleic acids and briefly summarizes some properties of the elimination voltammetry with linear scan (EVLS) method.
Journal ArticleDOI
Fifty Years of Nucleic Acid Electrochemistry
TL;DR: In this article, it was shown that OP signals respond to changes in DNA structure and can be used to study DNA denaturation, renaturation, premelting and DNA damage.
References
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Journal ArticleDOI
Sedimentation studies of the size and shape of dna.
TL;DR: Analytical zone sedimentation ( Vinograd, Bruner, Kent & Weigle, 1963) is shown to be a sensitive and reliable method for detecting differences in conformation and for determining the molecular weight of homogeneous phage DNA's.
Book
The biochemistry of the nucleic acids
TL;DR: The biochemistry of the nucleic acids is studied in detail in order to establish a clear picture of the role of phosphorous and nitrogen in the structure of DNA.
Journal ArticleDOI
Polarographic behavior of nucleosides and nucleotides of purines, pyrimidines, pyridines, and flavins.
Borivoj Janik,Philip J. Elving +1 more
Journal ArticleDOI
The influence of salts and pH on polarographic currents produced by denatured DNA
Viktor Brabec,E. Paleček +1 more
TL;DR: It was possible by using these methods to work with lower DNA concentrations and to measure at lower pH, and the dependences of limiting dc polarographic currents of denatured DNA onpH had S-shaped courses.
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