|Assistant Professor||Hisashi TADAKUMA|
Biomolecules that function in our bodies come in a variety of sizes ranging from several to hundreds of nanometers. This size falls precisely in the “meso” domain, which lies at the junction between micro and macro levels. A key difference in the environments of humans and biomolecules is that it is impossible for biomolecules to ignore thermal fluctuations because they are constantly exposed to changes in heat. Thus, unlike artificial machines, biomolecules are able to make skillful use of thermal fluctuations while functioning. For example, RNA polymerase is one-dimensionally diffused on DNA when searching for a promoter site. Our ultimate goal is to elucidate the how biomolecules operate.
Observing the motions of individual molecules and manipulating molecules directly are very useful for learning the working mechanisms of biomolecules. Therefore, we have developed techniques such as single-molecule imaging microscopy capable of directly observing the motion and structural changes of individual molecules, a method of manipulating molecules by grabbing molecules with optical or magnetic tweezers, and an apparatus for measuring the minute forces generated by molecules. Today, we are developing new imaging technologies and use these techniques to investigate the molecular mechanisms of biomolecules.
Current Research Programs
1. Analysis of biomolecular interactions with zero-mode waveguides
2. Analysis of gene expression using DNA origami
3. Development of intracellular local temperature measurement technology
1. Construction of integrated gene logic-chip. Masubuchi, T. et al. (2018) Natue Nanotechnology in press
2. Enrichment of ODMR-active nitrogen-vacancy centres in five-nanometre-sized detonation-synthesized nanodiamonds: Nanoprobes for temperature, angle and position. Sotoma, S. et al. (2018) Scientific reports 8(1), 5463-3802
3. Ca2+-associated triphasic pH changes in mitochondria during brown adipocyte activation. Hou, Y. et al. (2017) Molecular metabolism 6(8), 797-808
4. Gold Nanoshell-Mediated Remote Myotube Activation. Marino, A. et al. (2017) ACS nano 11(3), 2494-2508
5. A Beetle Flight Muscle Displays Leg Muscle Microstructure. Shimomura, T. et al. (2016) Biophysical journal 111(6), 1295-1303
6. The 10(5) gap issue between calculation and measurement in single-cell thermometry. Suzuki, M. et al. (2015) Nature Methods 12, 802-803
7. Single-Molecule Analysis of the Target Cleavage Reaction by the Drosophila RNAi Enzyme Complex Yao, C. et al. (2015) Molecular Cell 59, 125-132