Major research activity
Molecular Spectroscopy, Raman Microspectroscopy and Imaging, Biophysical Chemistry
We study a variety of molecular systems ranging from molecules in liquids/solutions to living cells, using advanced molecular spectroscopic techniques (in particular, those based on vibrational spectroscopy). Spectra are often referred to as “letters from the molecule”, and we decipher those letters in order to understand the interactions and dynamics that govern complex molecular systems. We will investigate structural dynamics in amyloid fibrils using low-frequency (‹200 cm-1) Raman spectroscopy and anharmonic vibrational coupling mechanisms in simple liquids using infrared electroabsorption spectroscopy.
The research of our laboratory is also focused on applications of Raman microspectroscopy and imaging to fundamental biology. We are interested in studying dynamic reorganization of intracellular molecules during cell division and metabolic processes in single living cells, as well as structured communities of bacteria called biofilms. Raman spectroscopy enables us to look into living cells in a nondestructive and label-free manner. Hence it makes untargeted, exploratory research feasible. To enhance the power of Raman microspectroscopy, we couple the technique with stable isotope (e.g., 2H and 13C) labeling and multivariate data analysis. James Watson said “life is simply a matter of chemistry”. Our goal is to make a significant and unique contribution to life science by establishing a new discipline “living cell physical chemistry”.
Major relevant publications
- C.-F. Chang, H. Okajima, H. Hamaguchi, and S. Shigeto, Imaging molecular crystal polymorphs and their polycrystalline microstructures in situ by ultralow-frequency Raman spectroscopy, Chem. Commun. 50, 12973-12976 (2014).
- Y.-T. Zheng, M. Toyofuku, N. Nomura, and S. Shigeto, Correlation of Carotenoid Accumulation with Aggregation and Biofilm Development in Rhodococcus sp. SD-74, Anal. Chem. 85, 7295-7301 (2013).
- J. Nishida, S. Shigeto, S. Yabumoto, and H. Hamaguchi, Anharmonic coupling of the CH-stretch and CH-bend vibrations of chloroform as studied by near-infrared electroabsorption spectroscopy, J. Chem. Phys. 137, 234501(1–9) (2012).
- H. N. Noothalapati Venkata and S. Shigeto, Stable Isotope-Labeled Raman Imaging Reveals Dynamic Proteome Localization to Lipid Droplets in Single Fission Yeast Cells, Chem. Biol. 19, 1373-1380 (2012).
- C.-K. Huang, M. Ando, H. Hamaguchi, and S. Shigeto, Disentangling Dynamic Changes of Multiple Cellular Components during the Yeast Cell Cycle by in Vivo Multivariate Raman Imaging, Anal. Chem. 84, 5661–5668 (2012).