TY - JOUR

T1 - Application of spectral methods for studying DNA damage induced by gamma-radiation

AU - Tankovskaia, Svetlana A.

AU - Kotb, Omar M.

AU - Dommes, Olga A.

AU - Paston, Sofia V.

PY - 2018/7/5

Y1 - 2018/7/5

N2 - 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 (3 mM–3.2 M) and containing MgCl 2, exposed to γ-radiation with the doses of 0–10 3 Gy. The melting temperatures of DNA in irradiated solutions at the doses of 0–50 Gy 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 Mg 2+ while keeping the total ionic strength constant (μ = 5 mM) 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.

AB - 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 (3 mM–3.2 M) and containing MgCl 2, exposed to γ-radiation with the doses of 0–10 3 Gy. The melting temperatures of DNA in irradiated solutions at the doses of 0–50 Gy 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 Mg 2+ while keeping the total ionic strength constant (μ = 5 mM) 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.

KW - Circular dichroism

KW - DNA damage

KW - DNA hydration

KW - DNA melting

KW - Ionizing radiation

KW - Ions

KW - Nucleobases destruction

KW - UV absorption spectroscopy

KW - HYDRATED DNA

KW - NUCLEIC-ACID

KW - RAMAN-SPECTROSCOPY

KW - CIRCULAR-DICHROISM

KW - CONFORMATIONAL-CHANGES

KW - CELLULAR-DNA

KW - PLASMID DNA

KW - IONIC-STRENGTH

KW - METAL-IONS

KW - Nudeobases destruction

KW - REAL-TIME

UR - http://www.scopus.com/inward/record.url?scp=85045392890&partnerID=8YFLogxK

U2 - 10.1016/j.saa.2018.04.011

DO - 10.1016/j.saa.2018.04.011

M3 - Article

VL - 200

SP - 85

EP - 92

JO - SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY

JF - SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY

SN - 1386-1425

ER -