Absorption of DNA in the region of vacuum-uv (3?25 eV)

Sontag, W.; Weibezahn, Karl-Friedrich

doi:10.1007/bf01327343

Cited by 30 publications

(16 citation statements)

References 14 publications

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“…For l<215 nm, water absorption begins to be significant and, therefore, the data of DNA absorption in aqueous solution for smaller wavelength has not been reported. Nevertheless, we complete the spectrum for l<215 nm with measurements made by Sontag and Weibezahn [18] for DNA film. This could be done because both spectra present an identical shape in the region l>215 nm.…”

Section: Oscillators' Optical Polarizability From Absorption Spectrummentioning

confidence: 99%

Optical Properties of DNA in Aqueous Solution

Umazano

Bertolotto

2008

J Biol Phys

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In the study of DNA electric birefringence, it is usual to use theories that consider that molecules in solution are small in relation to the light wavelength. In this work, we study the DNA electric birefringence using a broken-rod macroion (BRM) model composed of two cylindrical arms which does not restrict the size of the molecules. To achieve this, we include the inhomogeneity effect of the light electric field through the molecule and the interaction between its different parts. To analyze the interaction between a molecule and the incident beam of light, we apply the discrete dipole approximation (DDA), according to which each molecule is described as a finite array of electronic coupled oscillators. The electric birefringence is calculated from the oscillator polarizability. This is obtained from experimental data of electric birefringence saturation and from the increment of the solution refraction index in relation to that of the solvent. Furthermore, the oscillator polarizability is also estimated from DNA absorption spectrum using the KronigKramers relations. This allows us to analyze the contributions of the different absorption bands of DNA to the electric birefringence. We analyze the influence of the inhomogeneity of the light electric field and of the intramolecular interactions in the characterization of DNA optical properties using electric birefringence measurements.

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Section: Oscillators' Optical Polarizability From Absorption Spectrummentioning

confidence: 99%

Optical Properties of DNA in Aqueous Solution

Umazano

Bertolotto

2008

J Biol Phys

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“…5 ; see also Fig. They both absorb around 200 nm (region II), and continue absorbing Sontag & Weibezahn (1975); (b) Ito & Ito (1986); (c) Inagaki et al (1974). They both absorb around 200 nm (region II), and continue absorbing Sontag & Weibezahn (1975); (b) Ito & Ito (1986); (c) Inagaki et al (1974).…”

Section: Proteins and Amino Acids As Uv Screensmentioning

confidence: 82%

“…Our salmon sperm DNA sample was extracted with organic solvents to remove proteins and small molecules. Table 2, where we compare our results with already published DNA absorption spectra (Inagaki et al 1974 ;Sontag & Weibezahn 1975 ;Ito & Ito 1986), gives relative absorption intensities of DNA films at selected wavelengths, with respect to the intensity of the 260 nm band. Spectra in the dry and hydrated states were compared (Fig.…”

Section: Absorption Spectra Of Dnamentioning

confidence: 96%

“…Salmon sperm DNA belongs to the AT rich class, having a GC content of 41.2 % (Chargaff et al 1951). The DNA samples of Inagaki et al (1974) and those of Sontag & Weibezahn (1975) were from calf thymus, but the DNA sample of Ito & Ito (1986) The intensity measurements of Inagaki et al were indirectly determined, partly based on a Kramers-Kronig analysis of the index of refraction of the films. 2), using a DNA film dried onto a MgF 2 window and the same DNA dissolved in water.…”

Section: Absorption Spectra Of Dnamentioning

confidence: 99%

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Directed exospermia: I. Biological modes of resistance to UV light are implied through absorption spectroscopy of DNA and potential UV screens

Zalar¹,

Tepfer²,

Hoffmann

et al. 2007

International Journal of Astrobiology

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Panspermia, the dissemination of life through space, would require resistance to the conditions found in space, including UV light. All known life forms depend on DNA to store information. In an effort to understand the liabilities of DNA to UV light and modes of DNA protection in terrestrial life forms, we established UV-VUV (125-340 nm) absorption spectra for dry DNA and its polymerized components and mononucleotides, as well as for a selection of potential UV screens ubiquitous in all organisms, including proteins, selected amino acids and amines (polyamines and tyramine). Montmorillonite clay was included as a potential abiotic UV screen. Among the potential screens tested, adenosine triphosphate (ATP) appeared to be particularly attractive, because its UV absorption spectrum was similar to that of DNA. We suggest that the use of ATP in UV protection could have pre-dated its current role in energy transfer. Spectroscopy also showed that UV absorption varied according to nucleotide content, suggesting that base pair usage could be a factor in adaptation to given UV environments and the availability of UV screens.

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“…Increased absorption at λ < 160 nm may arises from σ-electron excitations mainly associated with the sugar-phosphate chain, and π→π* and σ→σ* transitions of the bases. A prominent peak in the energy-loss function near 21.6 eV is associated with a collective resonance involving all the valence electrons 4,5 . Energyabsorbing modes: excitations, so-called superexcitations, outer-and inner-shell ionizations affect the type and amount of DNA damage.…”

Section: Introductionmentioning

confidence: 98%

Damage to dry plasmid DNA induced by nanosecond XUV-laser pulses

et al. 2011

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Ionizing radiation induces a variety of DNA damages including single-strand breaks (SSBs), double-strand breaks (DSBs), abasic sites, modified sugar and bases. Most theoretical and experimental studies have been focused on DNA strand scissions, in particular production of DNA double-strand breaks. DSBs have been proven to be a key damage at a molecular level responsible for the formation of chromosomal aberrations, leading often to cell death. The complexity of lesions produced in DNA by ionizing radiations is thought to depend on the amount of energy deposited at the site of each lesion. We have studied the nature of DNA damage induced directly by the pulsed 46.9 nm radiation provided by a capillary-discharge Ne-like Ar laser (CDL). Different surface doses were delivered with a repetition rate of a few Hz and an average pulse energy ~ 1 µJ. A simple model DNA molecule, i.e., dried closed-circular plasmid DNA (pBR322), was irradiated. The agarose gel electrophoresis method was used for determination of both SSB and DSB yields. Results are compared with a previous study of plasmid DNA irradiated with a single sub-nanosecond 1-keV X-ray pulse produced by a large-scale, double-stream gas puff target, illuminated by sub-kJ, near-infrared (NIR) focused laser pulses at the PALS facility (Prague Asterix Laser System).

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Absorption of DNA in the region of vacuum-uv (3?25 eV)

Cited by 30 publications

References 14 publications

Optical Properties of DNA in Aqueous Solution

Optical Properties of DNA in Aqueous Solution

Directed exospermia: I. Biological modes of resistance to UV light are implied through absorption spectroscopy of DNA and potential UV screens

Damage to dry plasmid DNA induced by nanosecond XUV-laser pulses

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