Laboratory of Molecular Biophysics

Member

Director Toshimichi FUJIWARA
Assistant Professor Yoh MATSUKI
Ayako EGAWA
Toshihiko SUGIKI
Kenichi HARADA
Jun FUKAZAWA
Kyoko FURUITA
Technical Staff Naoyuki ABE

 

Correspondence

Tel 81-6-6879-8598
Fax 81-6-6879-8599
E-mail
URL http://www.protein.osaka-u.ac.jp/biophys/index.html

Research

We are studying the structure and function of the biological macromolecular systems mainly by using nuclear magnetic resonance (NMR). NMR provides information on the protein structure and dynamics at work with atomic resolution. Taking this advantage, we can understand biological activities for energy conversion and signal transduction systems. Since proteins play key roles through the intermolecular interactions in complex systems such as cells and supramolecules, we are also developing state-of-art solution and solid-state NMR methodologies including isotope-labeled sample preparation techniques and NMR bioinformatics. One of our programs for high-resolution solid-state NMR features high-field dynamic nuclear polarization (DNP) at cryogenic temperatures for a 10000-fold signal enhancement by using high-intensity terahertz light source, gyrotron.

fig.1_kinokozo
Fig. 1: NMR magnet for 600-MHz solid-state NMR on the left and 395-GHz gyrotron for high-intensity light source of terahertz-wave on the right. Hyperpolarization generated with these instruments increases the NMR sensitivity of proteins. This DNP-NMR spectrometer was developed in Institute for Protein Research. (Ref. 3)
fig.2_kinokozo
Fig. 2: 1H-13C HSQC spectra of methylated ubiquitin and methylated ubiquitin interacting with protein YUH1 shown on the left. Ubiquitin and YUH1 are shown in the complex (1CMX) by the ribbon and surface representation, respectively. Larger and smaller chemical shift changes are colored red and gray, respectively. This simple post-methylation method gives strong CH3 NMR signals for detecting the protein interactions. (Ref. 1)
fig.3_kinokozo
Fig. 3: Automatic solid-state NMR structural analysis of protein. 13C-NMR spectra of proteins in solids often show unresolved signals. Our spectral fitting softwane RESPLS enables chemical shift assignments and secondary structure prediction based on the databases PDBj and BMRB. This method simplifies the structural analysis by providing reliable information even for lyophilized states. (Ref. 2)

 

Current Research Programs

  1. Structure, interaction and function of protein systems as revealed by NMR
  2. Solution and solid-state NMR for cellular and supramolecular systems
  3. Development of high-resolution NMR using hyper-polarized spins

References

  1. Utilization of lysine 13C-methylation NMR for protein-protein interaction studies. Hattori Y, Furuita K, Ohki I, Ikegami T, Fukada H, Shirakawa M, Fujiwara T, Kojima C (2013) J. Biomol. NMR 55, 19-31.
  2. Secondary Structural Analysis of proteins based on 13C chemical shift assignments in unresolved solid-state NMR spectra enhanced by fragmented structure database, Ikeda K, Egawa A, Fujiwara T (2013) J. Biomol. NMR 55, 189-200.
  3. Helium-cooling and -spinning dynamic nuclear polarization for sensitivity-enhanced solid-state NMR at 14 T and 30 K, Matsuki Y, Ueda K, Idehara T, Ikeda R, Ogawa I, Nakamura S, Toda M, Anai T, Fujiwara T (2012) J. Magn. Reson. 225, 1-9.
  4. 14-3-3 proteins act as intracellular receptors for rice Hd3a florigen, Taoka K, Ohki I, Tsuji H, Furuita K, Hayashi K, Yanase T, Yamaguchi M, Nakashima C, Purwestri YA, Tamaki S, Ogaki Y, Shimada C, Nakagawa A, Kojima C, Shimamoto K (2011) Nature 476, 332-335.