Real-time probing of radical events with sulphide molecules

Autor: Gauduel, Yann, Glinec, Yannick, Malka, Victor
Přispěvatelé: Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Le, Thuy
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: Proceedings of SPIE, the International Society for Optical Engineering
Proceedings of SPIE, the International Society for Optical Engineering, SPIE, The International Society for Optical Engineering, 2007, 6449, pp.E1-E12
ISSN: 0277-786X
1996-756X
Popis: International audience; The physio-pathological roles of sulfide biomolecules in cellular environments involves redox processes and radical reactions that alter or protect the functional properties of enzymatic systems, proteins and nucleic acids repair. We focus on micromolar monitoring of sulfur-centered radical anions produced by direct electron attachment, using sulfide molecules (a thioether and a disulfide biomolecule) and two complementary spectroscopic approaches: low energy radiation femtochemistry (1-8 eV) and high energy radiation femtochemistry (2.5-15 MeV). The early step of a disulfide bond making RS. SR' from thiol molecules involves a very-short lived odd-electron bonded intermediate for which an excess electron is transiently localized by a preexisting two sulfide monomers complex. The reactive center of oxidized glutathione (cystamine), a major cytoplasmic disulfide biomolecule, is also used as sensor for the real-time IR investigation of effective reaction radius reff in homogenous aqueous environments and interfacial water of biomimetic systems. Femtosecond high-energy electrons beams, typically in the 2.5 - 15 MeV range, may conjecture the picosecond observation of primary radical events in nanometric radiation spurs. The real-time investigation of sulfide and disulfide molecules opens exciting opportunities for sensitisation of confined environments (aqueous groove of DNA, protein pockets, sub-cellular systems) to ionizing radiation. Low and high-energy femtoradical probing foreshadow the development of new applications in radiobiology (low dose effect at the nanometric scale) and anticancer radiotherapy (pro-drogue activation).
Databáze: OpenAIRE
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