INVESTIGADORES
PELLON MAISON Magali
artículos
Título:
PHOTOSENSITIZED CLEAVAGE OF PLASMIDIC DNA BY
Autor/es:
GONZALEZ, MICAELA M; PELLON-MAISON M; ALES-GANDOLFO, MATIAS A; GONZALEZ-BARO, MR; ERRA-BALSELLS, R; CABRERIZO, FM
Revista:
Organic & Biomolecular Chemistry
Editorial:
Royal Society of Chemistry
Referencias:
Año: 2010 vol. 8 p. 2543 - 2552
ISSN:
1477-0520
Resumen:
UV-A radiation (320400 nm) induces damages to the DNA molecule and its components through
photosensitized reactions. b-Carbolines (bCs), heterocyclic compounds widespread in biological
systems, participate in several biological processes and are able to act as photosensitizers. The
photosensitization of plasmidic DNA by norharmane in aqueous solution under UV-A radiation was
studied. The effect of pH was evaluated and the participation of reactive oxygen species (ROS), such as
hydroxyl radical (HOÓ), superoxide anion (O2b-Carbolines (bCs), heterocyclic compounds widespread in biological
systems, participate in several biological processes and are able to act as photosensitizers. The
photosensitization of plasmidic DNA by norharmane in aqueous solution under UV-A radiation was
studied. The effect of pH was evaluated and the participation of reactive oxygen species (ROS), such as
hydroxyl radical (HOÓ), superoxide anion (O2Ó), superoxide anion (O2
Ó-) and singlet oxygen (1O2) was investigated. A strong
dependence of the photosensitized DNA relaxation on the pH was observed. The extent of the reaction
was shown to be higher in the experiments performed at pH 4.7 than those performed at pH 10.2. As
was expected, an intermediate extent of the reaction was observed at physiological pH (pH 7.4). Kinetic
studies using ROS scavengers revealed that the chemical reactions between ROS and DNA are not the
main pathways responsible for the damage of DNA. Consequently, the predominant mechanism
yielding the DNA strand break takes place most probably via a type I mechanism (electron transfer)
fromthe single excited state (S1) of the protonated form of norharmane (1[nHoH+]*). Additional
information about the nature of the norharmane electronic excited states involved in the photocleavage
reaction was obtained by using the N-methyl derivative of norharmane (N-methyl-norharmane).-) and singlet oxygen (1O2) was investigated. A strong
dependence of the photosensitized DNA relaxation on the pH was observed. The extent of the reaction
was shown to be higher in the experiments performed at pH 4.7 than those performed at pH 10.2. As
was expected, an intermediate extent of the reaction was observed at physiological pH (pH 7.4). Kinetic
studies using ROS scavengers revealed that the chemical reactions between ROS and DNA are not the
main pathways responsible for the damage of DNA. Consequently, the predominant mechanism
yielding the DNA strand break takes place most probably via a type I mechanism (electron transfer)
fromthe single excited state (S1) of the protonated form of norharmane (1[nHoH+]*). Additional
information about the nature of the norharmane electronic excited states involved in the photocleavage
reaction was obtained by using the N-methyl derivative of norharmane (N-methyl-norharmane).via a type I mechanism (electron transfer)
fromthe single excited state (S1) of the protonated form of norharmane (1[nHoH+]*). Additional
information about the nature of the norharmane electronic excited states involved in the photocleavage
reaction was obtained by using the N-methyl derivative of norharmane (N-methyl-norharmane).1) of the protonated form of norharmane (1[nHoH+]*). Additional
information about the nature of the norharmane electronic excited states involved in the photocleavage
reaction was obtained by using the N-methyl derivative of norharmane (N-methyl-norharmane).N-methyl derivative of norharmane (N-methyl-norharmane).