scholarly journals Thymine dissociation and dimer formation: A Raman and synchronous fluorescence spectroscopic study

2021 ◽  
Vol 118 (6) ◽  
pp. e2025263118
Author(s):  
Anushka Nagpal ◽  
Dinesh Dhankhar ◽  
Thomas C. Cesario ◽  
Runze Li ◽  
Jie Chen ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Uv Irradiation ◽  
Spectroscopic Data ◽  
Irradiation Dose ◽  
Synchronous Fluorescence ◽  
Dimer Formation ◽  
Thymine Dimer ◽  
Calf Thymus ◽  
Thymine Dimers ◽  
Bacteria Inactivation

In this study, absorption, fluorescence, synchronous fluorescence, and Raman spectra of nonirradiated and ultraviolet (UV)-irradiated thymine solutions were recorded in order to detect thymine dimer formation. The thymine dimer formation, as a function of irradiation dose, was determined by Raman spectroscopy. In addition, the formation of a mutagenic (6-4) photoproduct was identified by its synchronous fluorescence spectrum. Our spectroscopic data suggest that the rate of conversion of thymine to thymine dimer decreases after 20 min of UV irradiation, owing to the formation of an equilibrium between the thymine dimers and monomers. However, the formation of the (6-4) photoproduct continued to increase with UV irradiation. In addition, the Raman spectra of nonirradiated and irradiated calf thymus DNA were recorded, and the formation of thymine dimers was detected. The spectroscopic data presented make it possible to determine the mechanism of thymine dimer formation, which is known to be responsible for the inhibition of DNA replication that causes bacteria inactivation.

Ultraviolet light induced thymine dimers and repair processes in the alga Eudorina elegans

1972 ◽  
Vol 18 (12) ◽  
pp. 1809-1815 ◽  
Author(s):  
C. L. Kemp ◽  
M. S. Tsao ◽  
G. Thorson
Keyword(s):  
Visible Light ◽  
Ultraviolet Light ◽  
Green Alga ◽  
Uv Irradiation ◽  
Excision Repair ◽  
Uv Exposure ◽  
Dark Repair ◽  
Thymine Dimer ◽  
Thymine Dimers ◽  
Cellular Dna

A fraction of the cellular DNA of the colonial green alga Eudorina elegans strain 1193 can be specifically labeled with 3H-thymidine but not by 3H-thymine. Ultraviolet (UV) irradiation of E. elegans leads to the production of thymine dimers as determined by extraction, hydrolysis, and chromatography of 3H-thymidine-labeled cells. Removal of dimers occurs by processes involving visible light (photoreactivation), but dark repair (excision repair) has not been detected in the labeled fraction. A relationship between UV exposure and thymine dimer production has been determined.

Molecular Transformations in DNA under the Influence of UV-radiation

2020 ◽  
Vol 04 ◽  
Author(s):  
Vigen G. Barkhudaryan ◽  
Gayane V. Ananyan ◽  
Nelli H. Karapetyan
Keyword(s):  
Uv Radiation ◽  
Uv Irradiation ◽  
Absorption Spectroscopy ◽  
Calf Thymus Dna ◽  
Dilute Solutions ◽  
Concentrated Solutions ◽  
Buffer Solution ◽  
Low Concentration ◽  
Calf Thymus ◽  
Dna Solutions

Background: The processes of destruction and crosslinking of macromolecules occur simultaneously under the influence of ultraviolet (UV) radiation in synthetic polymers, dry DNA and their concentrated solutions. Objective: The effect of UV radiation on calf thymus DNA in dilute solutions subjected to UV- irradiation was studied in this work. Method: The calf thymus DNA was studied in dilute solutions using viscometry, absorption spectroscopy and electrophoresis. Results: It was shown, that at a low concentration of DNA in the buffer solution ([DNA] = 85 μg / ml) under the influence of UV radiation, the processes of destruction of macromolecules and an increase in their flexibility predominate, which is accompanied by a gradual decrease in the viscosity of their solution. In addition, due to the low concentration of the solution, intramolecular crosslinking of macromolecules predominates, which also reduces their size and, consequently, the viscosity of the solution. Conclusion: It was concluded, that in dilute DNA solutions, due to the predominance of the processes of intramolecular crosslinking of macromolecules over intermolecular, only constant processes of decreasing the sizes of DNA macromolecules occur. As a result, its solubility remains virtually unchanged during UV irradiation. The described comments are also excellently confirmed by the results of absorption spectroscopy and electrophoresis

Laser Raman spectra of calf thymus histone complexes

1984 ◽  
Vol 15 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Jean-Jacques Jutier ◽  
Rodrigue Savoie ◽  
Marie Pigeon-Gosselin ◽  
Paul Nadeau ◽  
Peter N. Lewis
Keyword(s):  
Raman Spectra ◽  
Laser Raman ◽  
Calf Thymus ◽  
Laser Raman Spectra

DETECTION OF CYCLOBUTANE THYMINE DIMERS IN DNA OF HUMAN CELLS WITH MONOCLONAL ANTIBODIES RAISED AGAINST A THYMINE DIMER- CONTAINING TETRANUCLEOTIDE

1988 ◽  
Vol 48 (5) ◽  
pp. 627-633 ◽  
Author(s):  
Len Roza ◽  
Kees J. M. Wulp ◽  
Sandra J. MacFarlane ◽  
Paul H. M.Lohman ◽  
Robert A. Baan
Keyword(s):  
Monoclonal Antibodies ◽  
Human Cells ◽  
Thymine Dimer ◽  
Thymine Dimers

scholarly journals Flavonols Protect Against UV Radiation-Induced Thymine Dimer Formation in an Artificial Skin Mimic

2015 ◽  
Vol 18 (4) ◽  
pp. 600 ◽  
Author(s):  
Sabia Maini ◽  
Brian M. Fahlman ◽  
Ed S. Krol
Keyword(s):  
Uv Radiation ◽  
Artificial Skin ◽  
Uvb Radiation ◽  
Skin Damage ◽  
Dimer Formation ◽  
Thymine Dimer ◽  
Matrix Metalloproteinase 1 ◽  
Pyrimidine Dimers ◽  
Limit Of Quantitation ◽  
Radiation Induced

Purpose: Exposure of skin to ultraviolet light has been shown to have a number of deleterious effects including photoaging, photoimmunosuppression and photoinduced DNA damage which can lead to the development of skin cancer.  In this paper we present a study on the ability of three flavonols to protect EpiDerm™, an artificial skin mimic, against UV-induced damage. Methods: EpiDerm™ samples were treated with flavonol in acetone and exposed to UVA (100 kJ/m2 at 365 nm) and UVB (9000 J/m2 at 310 nm) radiation.  Secretion of matrix metalloproteinase-1 (MMP-1) and tumor necrosis factor-α (TNF-a) were determined by ELISA, cyclobutane pyrimidine dimers were quantified using LC-APCI-MS. Results: EpiDerm ™ treated topically with quercetin significantly decreased MMP-1 secretion induced by UVA (100 µM) or UVB (200 µM) and TNF-a secretion was significantly reduced at 100 µM quercetin for both UVA and UVB radiation.  In addition, topically applied quercetin was found to be photostable over the duration of the experiment.  EpiDerm™ samples were treated topically with quercetin, kaempferol or galangin (52 µM) immediately prior to UVA or UVB exposure, and the cyclobutane thymine dimers (T-T (CPD)) were quantified using an HPLC-APCI MS/MS method.  All three flavonols significantly decreased T-T (CPD) formation in UVB irradiated EpiDerm™, however no effect could be observed for the UVA irradiation experiments as thymine dimer formation was below the limit of quantitation.  Conclusions: Our results suggest that flavonols can provide protection against UV radiation-induced skin damage through both antioxidant activity and direct photo-absorption. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

scholarly journals Application of Bayesian Super-Resolution to Spectroscopic Data for Precise Characterization of Spectral Peak Shape

2022 ◽  
Author(s):  
Kota Tsujimori ◽  
Jun Hirotani ◽  
Shunta Harada
Keyword(s):  
Raman Spectra ◽  
Spectroscopic Data ◽  
Super Resolution ◽  
Spectral Peak ◽  
Peak Shape ◽  
Si Substrate ◽  
Precise Characterization ◽  
Data Points ◽  
The Ideal

AbstractThe number of data points of digitally recorded spectra have been limited by the number of multichannel detectors employed, which sometimes impedes the precise characterization of spectral peak shape. Here we describe a methodology to increase the number of data points as well as the signal-to-noise (S/N) ratio by applying Bayesian super-resolution in the analysis of spectroscopic data. In our present method, first, the hyperparameters for the Bayesian super-resolution are determined by a virtual experiment imitating actual experimental data, and the precision of the super-resolution reconstruction is confirmed by the calculation of errors from the ideal values. For validation of the super-resolution reconstruction of spectroscopic data, we applied this method to the analysis of Raman spectra. From 200 Raman spectra of a reference Si substrate with a data interval of about 0.8 cm−1, super-resolution reconstruction with a data interval of 0.01 cm−1 was successfully achieved with the promised precision. From the super-resolution spectrum, the Raman scattering peak of the reference Si substrate was estimated as 520.55 (+0.12, −0.09) cm−1, which is comparable to the precisely determined value reported in previous works. The present methodology can be applied to various kinds of spectroscopic analysis, leading to increased precision in the analysis of spectroscopic data and the ability to detect slight differences in spectral peak positions and shapes.

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