Dynamic phenomena in biophysics


  • Prof. Leonas Valkūnas 
  • Dr. Jevgenij Chmeliov 
  • Dr. Andrius Gelžinis 
  • Dr. Gediminas Trinkūnas 
  • Dr. Marijonas Tutkus 
Investigation of dynamic phenomena taking place in various biophysical systems on a molecular level is one of the modern branches of science that has emerged at the interplay of physics, chemistry, biology, and mathematics. These biophysical systems involve complex molecular systems that perform various vitally important biological functions (like light harvesting in photosynthesis, trans-membrane charge transfer in the living cells, image registration in the eye’s receptors, information encoding in the DNA molecules, etc.) and are governed by the physical and chemical properties of their constituents—proteins, pigments, nucleotides, etc. Dynamic phenomena in these molecular systems exhibit very broad scaling in both time (from femtosecond to minutes) and space (from angstroms to micrometers) domains, thus their detailed investigation requires laboratory equipment of very high temporal and spectral resolution. To understand these phenomena occurring at the intersection of the classical and quantum description as well as to explain the experimentally observed effects, the development of the data analysis algorithms, theoretical methods and computer modelling also become extremely important.
Recently, a lot of attention in the laboratory is paid to the molecular processes in photosynthesis and photoprotection. We investigate various photo-induced processes occurring in light-harvesting systems from plants, alga and phototrophic bacteria: light absorption, transfer of the generated electronic excitation via network of pigment molecules, utilization of this excitation energy for charge separation as well as its safely dissipation as heat to avoid any photodamage during high-light illumination condition. We actively collaborate with other scientific groups in London, Amsterdam, Paris, Lund, Michigan, etc., perform ultrafast pump-probe and fluorescence measurements and apply single-molecule microscopy techniques to analyze samples obtained from the aforementioned laboratories, analyze the collected experimental data, and perform the computer modelling of the underlying phenomena.

Selected publications (2015–2019)
  1. M. Tutkus, F. Saccon, J. Chmeliov, O. Venckus, I. Ciplys, A. V. Ruban, L. Valkunas, Single-molecule microscopy studies of LHCII enriched in Vio or Zea, Biochim. Biophys. Acta, Bioenerg. 1860, 499–507, 2019.
  2. A. Gelzinis, R. Augulis, V. Butkus, B. Robert, L. Valkunas, Two-dimensional spectroscopy for non-specialists, Biochim. Biophys. Acta, Bioenerg. 1860, 271–285, 2019.
  3. M. Tutkus, P. Akhtar, J. Chmeliov, F. Gorfol, G. Trinkunas, P. H. Lambrev, L. Valkunas, Fluorescence Microscopy of Single Liposomes with Incorporated Pigment–Proteins, Langmuir 34, 14410–14418, 2019.
  4. M. J. Llansola-Portoles, K. Redeckas, S. Streckaite, C. Ilioaia, A. A. Pascal, A. Telfer, M. Vengris, L. Valkunas, B. Robert, Lycopene crystalloids exhibit singlet exciton fission in tomatoes, Phys. Chem. Chem. Phys. 20, 8640–8646, 2018.
  5. S. Farooq, J. Chmeliov, E. Wientjes, R. Koehorst, A. Bader, L. Valkunas, G. Trinkunas, H. van Amerongen, Dynamic feedback of the photosystem II reaction centre on photoprotection in plants, Nat. Plants 4, 225–231, 2018.
  6. A. Gelzinis, J. Chmeliov, A. V. Ruban, L. Valkunas, Can red-emitting state be responsible for fluorescence quenching in LHCII aggregates?, Photosynth. Res. 135, 275–284 2018.
  7. G. Trinkunas, J. Chmeliov, Fluctuating Antenna Model: Applications and Prospects, Lith. J. Phys. 58, 379–390, 2018.
  8. M. Tutkus, J. Chmeliov, D. Rutkauskas, A. V. Ruban, L. Valkunas, Influence of the Carotenoid Composition on the Conformational Dynamics of Photosynthetic Light-Harvesting Complexes, J. Phys. Chem. Lett. 8, 5898–5906, 2017.
  9. A. Gelzinis, D. Abramavicius, J. P. Ogilvie, L. Valkunas, Spectroscopic properties of photosystem II reaction center revisited, J. Chem. Phys. 147, 115102, 2017.
  10. K. F. Fox, V. Balevicius Jr., J. Chmeliov, L. Valkunas, A. V. Ruban, C. D. P. Duffy, The carotenoid pathway: what is important for excitation quenching in plant antenna complexes?, Phys. Chem. Chem. Phys. 19, 22957–22968, 2017.
  11. J. Pan, A. Gelzinis, V. Chorosajev, M. Vengris, S. S. Senlik, J.-R. Shen, L. Valkunas, D. Abramavicius, J. P. Ogilvie, Ultrafast energy transfer within the photosystem II core complex, Phys. Chem. Chem. Phys. 19, 15356–15367, 2017.
  12. V. Butkus, J. Alster, E. Bašinskaite, R. Augulis, P. Neuhaus, L. Valkunas, H. L. Anderson, D. Abramavicius, D. Zigmantas, Discrimination of Diverse Coherences Allows Identification of Electronic Transitions of a Molecular Nanoring, J. Phys. Chem. Lett. 8, 2344–2349, 2017.
  13. J. M. Gruber, P. Xu, J. Chmeliov, T. P. J. Kruger, M. T. A. Alexandre, L. Valkunas, R. Croce, R. van Grondelle, Dynamic quenching in single photosystem II supercomplexes, Phys. Chem. Chem. Phys. 18, 25852–25860, 2016.
  14. J.  Chmeliov, A. Gelzinis, E. Songaila, R. Augulis, C. D. P. Duffy, A. V. Ruban, L. Valkunas, The nature of self-regulation in photosynthetic light-harvesting antenna, Nat. Plants 2, 16045, 2016.
  15. S. Farooq, J. Chmeliov, G. Trinkunas, L. Valkunas, H.  van Amerongen, Is There Excitation Energy Transfer between Different Layers of Stacked Photosystem-II-Containing Thylakoid Membranes?, J. Phys. Chem. Lett. 7, 1406–1410, 2016.
  16. D. Abramavicius, L. Valkunas, Artificial Photosynthesis: Theoretical Background, in: Artificial Photosynthesis, ed. B. Robert, Advances in Botanical Research 79, 129–167, 2016.
  17. D. Abramavicius, L. Valkunas, Role of coherent vibrations in energy transfer and conversion in photosynthetic pigment–protein complexes, Photosynth. Res. 127, 33–47, 2016.
  18. J. Chmeliov, G. Trinkunas, H. van Amerongen, L. Valkunas, Excitation migration in fluctuating light-harvesting antenna systems, Photosynth. Res. 127, 49–60, 2016.
  19. E. G. Petrov, B. Robert, S. H. Lin, L. Valkunas, Theory of Triplet Excitation Transfer in the Donor-Oxygen-Acceptor System: Application to Cytochrome b(6)f, Biophys. J. 109, 1735–1745, 2015.
  20. V. Butkus, A. Gelzinis, R. Augulis, A. Gall, C. Buechel, B. Robert, D. Zigmantas, L. Valkunas, D. Abramavicius, Coherence and population dynamics of chlorophyll excitations in FCP complex: Two-dimensional spectroscopy study, J. Chem. Phys. 142, 212414, 2015.
  21. A. Gelzinis, V. Butkus, E. Songaila, R. Augulis, A. Gall, C. Buechel, B. Robert, D. Abramavicius, D. Zigmantas, L. Valkunas, Mapping energy transfer channels in fucoxanthin-chlorophyll protein complex, Biochim. Biophys. Acta, Bioenerg. 1847, 241–247, 2015.
  22. J. M. Gruber, J. Chmeliov, T. P. J. Krüger, L. Valkunas, R. van Grondelle, Singlet–triplet annihilation in single LHCII complexes, Phys. Chem. Chem. Phys. 17, 19844–19853, 2015.
  23. J. Chmeliov, W. P. Bricker, C. Lo, E. Jouin, L. Valkunas, A. V. Ruban, C. D. P. Duffy, An ‘all pigment’ model of excitation quenching in LHCII, Phys. Chem. Chem. Phys. 17, 15857–15867, 2015.