Tankovskaia SA, Kotb OM, Dommes OA, Paston SV. Application of spectral methods for studying DNA damage induced by gamma-radiation.
SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018;
200:85-92. [PMID:
29674243 DOI:
10.1016/j.saa.2018.04.011]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 06/08/2023]
Abstract
Spectral methods can provide a variety of possibilities to determine several types of radiation-induced DNA damage, such as nucleobase destruction and local denaturation. DNA UV absorption and CD spectra measured at room temperature undergo noticeable alteration under the action of γ-radiation. We have applied the Spirin method of total nucleobases determination, and have measured the molar extinction coefficient of DNA and DNA CD spectra for solutions with different NaCl concentrations (3mM-3.2M) and containing MgCl2, exposed to γ-radiation with the doses of 0-103Gy. The melting temperatures of DNA in irradiated solutions at the doses of 0-50Gy were obtained with the help of spectrophotometric melting. It was found that the amount of destructed nucleobases and radiation-induced loss of DNA helicity significantly decreases with the rise of the ionic strength of the irradiated solution. Substitution of a portion of Na+ ions on Mg2+ while keeping the total ionic strength constant (μ=5mM) does not affect the considered radiation effects. The role of the structure and composition of the DNA secondary hydration layer in the radiation-induced damages is discussed.
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