NIBB Departments

Division of Photophysical Biology

Staff

Research Summary

Photosynthetic organisms capture sunlight to produce carbohydrates. While this is a well-known photoreaction, the molecular mechanism is unclear yet. In particular, a fundamental question is how the localized light stimulation caused by the photoexcitation of a pigment cascades from molecules, proteins, and biological membranes to cells. By developing our own spectromicroscopic techniques for spatial, temporal, and energetic decomposition analysis of photoreaction processes in biological systems, we elucidate the regulation principle of the photoreaction, seamlessly correlating molecular to higher-order membrane systems. Furthermore, we explore new research fields such as spectral analysis of extinct photosynthetic organisms, fluctuation-based spectroscopy, and quantum measurements of biological systems.

A variety of home-built microscopes allows to elucidate the regulation principle of biological photoreactions.

Research Projects

• Photosynthetic femtosecond energy transfer regulated by structural heterogeneity (using ultrafast transient absorption microscopy)
• Physiological role of fluctuation dynamics related to photosynthetic pigment protein (using time-resolved fluorescence spectral microscopy)
• Photoreaction processes in photosynthetic protein supercomplexes (using superresolution fluorescence/absorption microscopy)
• Relationship between excitonic states and energy transfer in biological and biomimicked light-harvesting systems (using fluorescence microscopy with point excitation and widefield imaging)
• Functional analysis of ancient photosynthetic proteins (using multimodal microscopy)

Selected Publications

Kondo, T., Mutoh, R., Arai, S., Kurisu, G., Oh-Oka, H., Fujiyoshi, S., and Matsushita, M. (2022). Energy transfer fluctuation observed by single-molecule spectroscopy of red-shifted bacteriochlorophyll in the homodimeric photosynthetic reaction center. J. Chem. Phys. 156, 105102.

Moya, R., Kondo, T., Norris, A. C., and Schlau-Cohen, G. S. (2021). Spectrally-tunable femtosecond single-molecule pump-probe spectroscopy. Opt. Express 29, 28246-28256.

Kondo, T., Mutoh, R., Tabe, H., Kurisu, G., Oh-Oka, H., Fujiyoshi, S., and Matsushita, M. (2020). Cryogenic single-molecule spectroscopy of the primary electron acceptor in the photosynthetic reaction center. J. Phys. Chem. Lett. 11, 3980-3986.

Kondo, T., Gordon, J. B., Pinnola, A., Dall'Osto, L., Bassi, R., and Schlau-Cohen, G. S. (2019). Microsecond and millisecond dynamics in the photosynthetic protein LHCSR1 observed by single-molecule correlation spectroscopy. Proc. Natl. Acad. Sci. USA 116, 11247-11252.

Kondo, T., Chen, W. J., and Schlau-Cohen, G.S. (2017). Single-molecule fluorescence spectroscopy of photosynthetic systems. Chem. Rev. 117, 860-898.

Kondo, T., Pinnola, A., Chen, W. J., Dall'Osto, L., Bassi, R., and Schlau-Cohen, G. S. (2017). Single-molecule spectroscopy of LHCSR1 protein dynamics identifies two distinct states responsible for multi-timescale photosynthetic photoprotection. Nat. Chem. 9, 772-778.