Dimitra Markovitsi is a Greek-French photochemist.[1] She is currently an Emeritus Research Director at the French National Center for Scientific Research (CNRS).[2] She pioneered studies on the electronically excited states of liquid crystals and made significant advances to the understanding of processes triggered in DNA upon absorption of UV radiation. The two facets of her work have been the subject of a recent Marie Skodowska Curie European training network entitled "Light DyNAmics - DNA as a training platform for photodynamic processes in soft materials."[3]

Early life

1954 marks the birth of Markovitsi, daughter of Tryfon and Eleftheria, in Athens. From 1958 to 1969, she resided at Krya Vrysi, Pella. Then she returned to Athens, where she finished with a degree in chemical engineering from the National Technical University (1978). Thanks to a scholarship from the French government, she relocated to France, where she earned a "Diplôme d'Etudes Approfondies" (equivalent to a Master's degree) in 1979 on "Energy and Pollution" from the Université Paris VII and, later, a Ph.D. in Chemistry from the Louis Pasteur University at Strasbourg (1983).[4]

Research work

Dimitra Markovitsi's areas of research interest include photophysics and photochemistry in the condensed phase, time-resolved optical spectroscopy (absorption, fluorescence), excited states, energy, and charge transfer, charge separation, ionization, radical formation, photodamage, UV-induced primary processes in DNA (excited states, intrinsic fluorescence, electron ejection, oxidative damage) and G-quadruplexes.

Markovitsi studied the dimensionality of excitation transport in columnar phases.[5] She discussed the effect of orientational disorder on the electronic excited states and introduced a model based on the exciton theory and quantum chemistry computations.

She published the first studies investigating the effect of structural disorder on the excited states of double helices and guanine quadruplexes.[6] Simultaneously, she explored the behavior of the intrinsic DNA fluorescence from femtoseconds to nanoseconds.[7] She provided evidence of the occurrence of excitation transport between nucleobases and the collective nature of Franck-Condon states.[8][9] She reported the first spectroscopic investigation on DNA excited states in the UVA region; despite their very poor absorption, such excited states may contribute to the deterioration of the genetic code by solar light, whose UVA intensity is greater than that of UVB and UVC.[10] She identified an unanticipated phenomenon: low-energy UV radiation can ionize DNA multimers (but not their monomeric components), generating electron holes in the nucleobases. The latter radical species are precursors of oxidative damage and provide promise for nanodevices based on photoconductivity. She demonstrated that the photoionization of guanine quadruplexes can be adjusted by varying their structural parameters.[11][12]

Markovitsi also investigated DNA reaction dynamics on nanosecond to millisecond timescales. This work focuses on the dimerization of nucleobases and the deprotonation and tautomerization of the guanine radical. Her research revealed the anisotropic character of such events, which are highly dependent on the local DNA environment, rendering the conventional models of chemical kinetics inadequate for describing them.[13]

Markovitsi’s work has been published in collective books, including the “Handbook of Organic Photochemistry and Photobiology.[14]

Career

While at Strasbourg in 1981, Markovitsi joined the CNRS. Then she relocated to the Paris area, where she worked from 1985 until 2021 in the CEA Paris-Saclay, in joint research Laboratories of the CNRS and the French Alternative Energies and Atomic Energy Commission. From 2001 to 2014, she was the director of the Francis Perrin Laboratory (Laboratoire Francis-Perrin). After being appointed Emeritus Research Director, she moved to the Institut de Chimie Physique - Université Paris-Saclay.[15]

Markovitsi served as president of the European Photochemistry Association from 2007 to 2010,[16] and since 2014 she is the president of the International Foundation for Photochemistry.

Relevant publications

  • D. Markovitsi, Processes triggered in guanine quadruplexes by direct absorption of UV radiation: From fundamental studies toward optoelectronic biosensors, Photochem. Photobiol. 2023, doi.org/10.1111/php.13826.
  • Balanikas, E.; Banyasz, A.; Baldacchino, G.; Markovitsi, D. Deprotonation Dynamics of Guanine Radical Cations. Photochem. Photobiol. 2022, 98, 523-531.[17]
  • Gustavsson, T.; Markovitsi, D. Fundamentals of the Intrinsic DNA Fluorescence. Acc. Chem. Res. 2021, 54, 1226-1235.[18]
  • Balanikas, E.; Banyasz, A.; Douki, T.; Baldacchino, G.; Markovitsi, D. Guanine Radicals Induced in DNA by Low-Energy Photoionization. Acc. Chem. Res. 2020, 53, 1511–1519.[19]
  • Banyasz, A.; Vay, I.; Changenet-Barret, P.; Gustavsson, T.; Douki, T.; Markovitsi, D. Base-pairing enhances fluorescence and favors cyclobutane dimer formation induced upon absorption of UVA radiation by DNA. J. Am. Chem. Soc. 2011, 133, 5163-5165.[20]
  • Ecoffet, C.; Markovitsi, D.; Millie, P.; Lemaistre, J. Electronic excitations in organized molecular systems. A model for columnar aggregates of ionic compounds. Chem. Phys. 1993, 177, 629-643.[21]

References

  1. ↑ https://scholar.google.fr/citations?user=EP3jtcAAAAAJ&hl=fr
  2. ↑ "Dimitra Markovitsi". IRAMIS. Retrieved 2023-02-22.
  3. ↑ "Dr. Dimitra Markovitsi". lightdynamics.eu. Archived from the original on 2020-09-29.
  4. ↑ https://www.ipcms.fr/wp-content/uploads/2021/02/Theses_pour-le-web_040918.pdf
  5. ↑ Markovitsi, Dimitra (2003-01-01). "Energy Transport in Columnar Mesophases". Molecular Crystals and Liquid Crystals. 397 (1): 89–98. doi:10.1080/714965608. ISSN 1542-1406. S2CID 94842723.
  6. ↑ Bouvier, Benjamin; Dognon, Jean-Pierre; Lavery, Richard; Markovitsi, Dimitra; Millié, Philippe; Onidas, Delphine; Zakrzewska, Krystyna (2003-12-01). "Influence of Conformational Dynamics on the Exciton States of DNA Oligomers". The Journal of Physical Chemistry B. 107 (48): 13512–13522. doi:10.1021/jp036164u. ISSN 1520-6106.
  7. ↑ Gustavsson, Thomas; Markovitsi, Dimitra (2021-03-02). "Fundamentals of the Intrinsic DNA Fluorescence". Accounts of Chemical Research. 54 (5): 1226–1235. doi:10.1021/acs.accounts.0c00603. ISSN 0001-4842. PMID 33587613. S2CID 231937713.
  8. ↑ Markovitsi, Dimitra; Onidas, Delphine; Gustavsson, Thomas; Talbot, Francis; Lazzarotto, Elodie (2005-12-01). "Collective Behavior of Franckâˆ'Condon Excited States and Energy Transfer in DNA Double Helices". Journal of the American Chemical Society. 127 (49): 17130–17131. doi:10.1021/ja054955z. ISSN 0002-7863. PMID 16332029.
  9. ↑ Vayá, Ignacio; Gustavsson, Thomas; Douki, Thierry; Berlin, Yuri; Markovitsi, Dimitra (2012-07-18). "Electronic Excitation Energy Transfer between Nucleobases of Natural DNA". Journal of the American Chemical Society. 134 (28): 11366–11368. doi:10.1021/ja304328g. ISSN 0002-7863. PMID 22765050.
  10. ↑ Markovitsi, Dimitra (January 2016). "UV-induced DNA Damage: The Role of Electronic Excited States". Photochemistry and Photobiology. 92 (1): 45–51. doi:10.1111/php.12533. PMID 26436855. S2CID 5888870.
  11. ↑ E. Balanikas, L. Martinez-Fernadez, R. Improta, P. Podbevsek, G. Baldacchino and D. Markovitsi, "The Structural Duality of Nucleobases in Guanine Quadruplexes Controls Their Low-Energy Photoionization" J. Phys. Chem. Lett. 2021 Vol. 12 Pages 8309−8313, DOI: org/10.1021/acs.jpclett.1c01846
  12. ↑ Balanikas, Evangelos; Banyasz, Akos; Douki, Thierry; Baldacchino, Gérard; Markovitsi, Dimitra (2020-08-18). "Guanine Radicals Induced in DNA by Low-Energy Photoionization". Accounts of Chemical Research. 53 (8): 1511–1519. doi:10.1021/acs.accounts.0c00245. ISSN 0001-4842. PMID 32786340.
  13. ↑ E. Balanikas, A. Banyasz, G. Baldacchino and D. Markovitsi "Populations and Dynamics of Guanine Radicals in DNA strands: Direct versus Indirect Generation" Molecules 2019 Vol. 24 Pages 2347, DOI: 10.3390/molecules24132347
  14. ↑ CRC Handbook of Organic Photochemistry and Photobiology, A. Griesbeck, M. Oelgemöller and F. Ghetti eds., CRC Press 2012, ISBN 9781439899335
  15. ↑ Institut de chimie physique - Université Paris-Saclay
  16. ↑ "chemistry.as.miami.edu" (PDF).
  17. ↑ Balanikas, Evangelos; Banyasz, Akos; Baldacchino, GÃrard; Markovitsi, Dimitra (May 2022). "Deprotonation Dynamics of Guanine Radical Cations". Photochemistry and Photobiology. 98 (3): 523–531. doi:10.1111/php.13540. ISSN 0031-8655. PMID 34653259. S2CID 239004109.
  18. ↑ Gustavsson, Thomas; Markovitsi, Dimitra (2021-03-02). "Fundamentals of the Intrinsic DNA Fluorescence". Accounts of Chemical Research. 54 (5): 1226–1235. doi:10.1021/acs.accounts.0c00603. ISSN 0001-4842. PMID 33587613. S2CID 231937713.
  19. ↑ Balanikas, Evangelos; Banyasz, Akos; Douki, Thierry; Baldacchino, Grard; Markovitsi, Dimitra (2020-08-18). "Guanine Radicals Induced in DNA by Low-Energy Photoionization". Accounts of Chemical Research. 53 (8): 1511–1519. doi:10.1021/acs.accounts.0c00245. ISSN 0001-4842. PMID 32786340.
  20. ↑ Banyasz, Akos; Vayá, Ignacio; Changenet-Barret, Pascale; Gustavsson, Thomas; Douki, Thierry; Markovitsi, Dimitra (2011-04-13). "Base Pairing Enhances Fluorescence and Favors Cyclobutane Dimer Formation Induced upon Absorption of UVA Radiation by DNA". Journal of the American Chemical Society. 133 (14): 5163–5165. doi:10.1021/ja110879m. hdl:10251/28319. ISSN 0002-7863. PMID 21417388. S2CID 21990777.
  21. ↑ Ecoffet, Carole; Markovitsi, Dimitra; Milli, Philippe; Lemaistre, Jean-Pierre (1993-12-01). "Electronic excitations in organized molecular systems. A model for columnar aggregates of ionic compounds". Chemical Physics. 177 (3): 62943. doi:10.1016/0301-0104(93)85028-7. ISSN 0301-0104.
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