Exciton effects in dinucleotides and polynucleotides

Kononov, Alexei I.; Bakulev, V. M.; Rapoport, V. L.

doi:10.1016/1011-1344(93)87109-z

Cited by 21 publications

(25 citation statements)

References 5 publications

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“…There have been no direct experimental observations of long-range delocalization of excitations in NAs so far, in contrast to photosynthetic light-harvesting systems, for which such observation have been made using nonlinear absorption and fast transient absorption pump–probe spectroscopy ( 39–41 ). Experimental evidence based on steady-state fluorescence excitation and CD spectra suggest that excitons in single-stranded NAs are limited to two bases ( 42–45 ). Based on UV/IR pump–probe experiments, Fiebig et al.…”

Section: Introductionmentioning

confidence: 99%

DNA as UV light–harvesting antenna

Volkov

Reveguk

Serdobintsev

et al. 2017

Nucleic Acids Research

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The ordered structure of UV chromophores in DNA resembles photosynthetic light-harvesting complexes in which quantum coherence effects play a major role in highly efficient directional energy transfer. The possible role of coherent excitons in energy transport in DNA remains debated. Meanwhile, energy transport properties are greatly important for understanding the mechanisms of photochemical reactions in cellular DNA and for DNA-based artificial nanostructures. Here, we studied energy transfer in DNA complexes formed with silver nanoclusters and with intercalating dye (acridine orange). Steady-state fluorescence measurements with two DNA templates (15-mer DNA duplex and calf thymus DNA) showed that excitation energy can be transferred to the clusters from 21 and 28 nucleobases, respectively. This differed from the DNA–acridine orange complex for which energy transfer took place from four neighboring bases only. Fluorescence up-conversion measurements showed that the energy transfer took place within 100 fs. The efficient energy transport in the Ag–DNA complexes suggests an excitonic mechanism for the transfer, such that the excitation is delocalized over at least four and seven stacked bases, respectively, in one strand of the duplexes stabilizing the clusters. This result demonstrates that the exciton delocalization length in some DNA structures may not be limited to just two bases.

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Section: Introductionmentioning

confidence: 99%

DNA as UV light–harvesting antenna

Volkov

Reveguk

Serdobintsev

et al. 2017

Nucleic Acids Research

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“…Electronic coupling between nucleobases in DNA single and double strands is of great importance in photobiology and has spurred the interest of both theorists and experimentalists. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] It impacts on the photostability of DNA with respect to UV damage because it determines the nonradiative deexcitation pathways. One protection mechanism is fast nonradiative relaxation to the electronic ground state as has been observed to occur for single bases 14 and another is delocalisation of excitation energy over two or more nucleobases to prevent subsequent photochemical reactions.…”

Section: Introductionmentioning

confidence: 99%

Electronic coupling between cytosine bases in DNA single strands and i-motifs revealed from synchrotron radiation circular dichroism experiments

Holm

Nielsen

Kohler

et al. 2010

Phys. Chem. Chem. Phys.

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In this work we have recorded synchrotron radiation circular dichroism (SRCD) spectra from 180 nm to 360 nm of cytosine strands [(dC)(n), n = 1, 2, ..., 10] in aqueous solution at different pH values to reveal electronic coupling between bases in different ionisation states. The geometry of the strands is determined by the pH value and the strand length and the local organisation of the cytosines will determine the base-to-base interaction that impacts on the CD signal. At low pH where all bases are protonated, there is no signature of electronic coupling between the bases, and the SRCD spectrum is simply n times that of the n = 1 spectrum. At higher pH where all bases are neutral, the spectra for n > 1 differ from the monomer spectrum, which implies electronic coupling between bases. The correlation between the CD signal and n is linear, and the spatial extent of the excited state wavefunction is therefore over just two stacked bases both in the UV and VUV. At intermediate pH, the low-n spectra are different from the high-n spectra, and a transition is seen to occur at n = 6-8. We ascribe this behavior to the formation of i-motif structures between four (dC)(n) strands for high n.

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“…In excitation spectra of stacked dimers is observed a strong exciton splitting 3500 cm −1 , because the interplane distance is very small -3.0A (dipole-dipole interaction model). Earlier the stacking dimers with the same spectra of luminescence and its excitation were observed in works of our group for ApA at room temperature (water-salt solution) and at 77K (ethyleneglycol:water glass, 1:1, v) (Rapoport and Kononov, 1988;Kononov et al, 1993).…”

Section: P-28 Theoretical Study On Aggregates Of Seryl-histidine Andmentioning

confidence: 72%

Abstracts of Issol 2005, the 14th International Conference on the Origin of Life, Held in Beijing, from June 19–24, 2005

2006

Orig Life Evol Biosph

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Exciton effects in dinucleotides and polynucleotides

Cited by 21 publications

References 5 publications

DNA as UV light–harvesting antenna

DNA as UV light–harvesting antenna

Electronic coupling between cytosine bases in DNA single strands and i-motifs revealed from synchrotron radiation circular dichroism experiments

Abstracts of Issol 2005, the 14th International Conference on the Origin of Life, Held in Beijing, from June 19–24, 2005

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