Electron Transfer Between Bases in Double Helical DNA

Kelley, Shana O.; Barton, Jacqueline K.

doi:10.1126/science.283.5400.375

Cited by 874 publications

(752 citation statements)

References 37 publications

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“…1,23,24,26,27 Singlet energy transfer between bases has been observed for photo-induced electron transfer between guanine and 2-aminopurine (2AP), a fluorescent analog of guanosine and adenosine, and between guanine and 1,N6 ethenoadenine. 41 In that case, it was hypothesized that quenching of the fluorescent nucleotide (2AP or 1,N6-ethenoadenine) depends on the extent of stacking interaction of the fluorescent probe with flanking bases. These authors observed that 1,N6 ethenoadenine was not quenched as readily as 2AP, which was attributed to a lower stacking interaction of 1,N6 ethenoadenine with G. Another group found that energy transfer from bases to 2AP was increased at low temperature.…”

Section: Discussionmentioning

confidence: 99%

Fluorescence of unmodified oligonucleotides: A tool to probe G‐quadruplex DNA structure

Méndez

Szalai

2009

Biopolymers

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Fluorescence of unmodified oligonucleotides has not been exploited for guanine‐quadruplex (G‐quadruplex) characterization. We observe that G‐rich sequences fluoresce more strongly than duplex or single‐stranded DNA but much more weakly than fluorophores like fluorescein. This increase in the intrinsic fluorescence is not due to an increase in absorption at the excitation wavelength but rather to a change in the quantum yield. We show that unlabeled oligonucleotides that form G‐quadruplexes can be differentiated on the basis of their emission spectra from similar sequences that do not contain consecutive guanines. Intermolecular quadruplexes formed by the oligonucleotides 5′‐T4GnT4‐3′ (n = 4–10) display a nonlinear, but continuous, increase in emission intensity as the G content increases. The sequence 5′‐GGGT‐3′, which has been proposed to form a monomeric quadruplex and an interlocked quadruplex (Krishnan‐Ghosh et al. J Am Chem Soc 2004, 126, 11009), was compared with the similar sequence 5′‐TGGG‐3′, the structure of which has not been characterized. Both the maximum emission intensity and the spectral shape differ for these oligonucleotides as a function of sample preparation, indicating that different types of quadruplexes form for both sequences. Our work is the first to demonstrate that the suprastructure of G‐rich sequences can be probed using fluorescence signatures of unmodified oligonucleotides. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 841–850, 2009.This article was originally published online as an accepted preprint. The ”Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

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Section: Discussionmentioning

confidence: 99%

Fluorescence of unmodified oligonucleotides: A tool to probe G‐quadruplex DNA structure

Méndez

Szalai

2009

Biopolymers

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“…The double helical structure of DNA, with its π-stacked array of heterocyclic aromatic base pairs, allows DNA to serve as a medium for CT [41][42][43][44]. Long range DNA CT is efficient over distances of at least 200 Å [45] and displays exquisite sensitivity to mismatched or damaged base pairs [46][47][48][49].…”

Section: Electrochemical Investigation Of Muty and Endo IIImentioning

confidence: 99%

DNA repair glycosylases with a [4Fe–4S] cluster: A redox cofactor for DNA-mediated charge transport?

Boal

Yavin

Barton

2007

Journal of Inorganic Biochemistry

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The [4Fe-4S] cluster is ubiquitous to a class of base excision repair enzymes, in organisms ranging from bacteria to man, and was first considered as a structural element, owing to its redox stability under physiological conditions. When studied bound to DNA, two of these repair proteins (MutY and Endonuclease III from Escherichia coli) display DNA-dependent reversible electron transfer with characteristics typical of high potential iron proteins. These results have inspired a reexamination of the role of the [4Fe-4S] cluster in this class of enzymes. Might the [4Fe-4S] cluster be used as a redox cofactor to search for damaged sites using DNA-mediated charge transport, a process well known to be highly sensitive to lesions and mismatched bases? Described here are experiments demonstrating the utility of DNA-mediated charge transport in characterizing these DNA-binding metalloproteins, as well as efforts to elucidate this new function for DNA as an electronic signaling medium among the proteins.

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“…[52][53][54][55][56][57][58][59] Photophysical experiments have shown that in solution DNA charge-transport chemistry generally is sensitive to the stacking characteristics of donor and acceptors and is particularly efficient with well-coupled π-stacked intercalators. 7,8,19,20,75 The requisite features of the redox donor and acceptor have not been specifically addressed for DNA-mediated electrochemical charge-transport reactions. Here, we explore the characteristics of the donor/acceptor partners required for efficient DNA-mediated charge transport on DNA-modified surfaces.…”

Section: Introductionmentioning

confidence: 99%

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] The DNA π-stack is capable of mediating oxidative DNA damage over long molecular distances in a reaction that is sensitive to DNA sequence-dependent conformation and dynamics. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] A mixture of tunneling and hopping mechanisms has been proposed to account for this long-range chemistry, which is gated by dynamical variations within the stack. [32][33][34][35][36][37][38][39][40][41][42][43]…”

Section: Introductionmentioning

confidence: 99%

Intercalative Stacking: A Critical Feature of DNA Charge-Transport Electrochemistry

et al. 2003

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In electrochemistry experiments on DNA-modified electrodes, features of the redox probe that determine efficient charge transport through DNA-modified surfaces have been explored using methylene blue (MB + ) and Ru(NH 3 ) 6 3+ as DNA-binding redox probes. The electrochemistry of these molecules is studied as a function of ionic strength to determine the necessity of tight binding to DNA and the number of electrons involved in the redox reaction; on the DNA surface, MB + displays 2e -/1H + electrochemistry (pH 7) and Ru(NH 3 ) 6 3+ displays 1e -electrochemistry. We examine also the effect of electrode surface passivation and the effect of the mode (intercalation or electrostatic) of MB + and Ru(NH 3 ) 6 3+ binding to DNA to highlight the importance of intercalation for reduction by a DNA-mediated charge-transport pathway. Furthermore, in experiments in which MB + is covalently linked to the DNA through a σ-bonded tether and the ionic strength is varied, it is demonstrated that intercalative stacking rather than covalent σ-bonding is essential for efficient reduction of MB + . The results presented here therefore establish that efficient charge transport to the DNA-binding moiety in DNA films requires intercalative stacking and is mediated by the DNA base pair array.

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Electron Transfer Between Bases in Double Helical DNA

Cited by 874 publications

References 37 publications

Fluorescence of unmodified oligonucleotides: A tool to probe G‐quadruplex DNA structure

Fluorescence of unmodified oligonucleotides: A tool to probe G‐quadruplex DNA structure

DNA repair glycosylases with a [4Fe–4S] cluster: A redox cofactor for DNA-mediated charge transport?

Intercalative Stacking: A Critical Feature of DNA Charge-Transport Electrochemistry

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