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SAKURAZAWA Shigeru 教授

SAKURAZAWA, Shigeru Professor

Job introductions

Both machines and living organisms function through the complex interplay of countless parts. However, creating living organisms is not easy. This is because the interactions between parts are fundamentally different between machines and living organisms.

To put the difference simply, it's like the difference between an orchestra with sheet music and a conductor, and an improvisational free jazz band with neither. The former can perform even if the members are complete strangers, and they can perform the same piece over and over again. However, the latter starts with "Nice to meet you," and the communication that takes place between them at any given moment is the performance itself, so it's usually impossible to repeat the exact same performance. In both cases, the result is "music," but the processes by which it is created are completely different.

In short, the difference lies in the mechanism that governs the entire system. Every component of a machine is given a clock and a schedule, but living organisms do not. Although the operation of the components of living organisms is left solely to communication with the components closest to them, living organisms are able to perform coordinated actions as a whole. What is the secret behind this? That is my research.

Currently, my research focuses on the themes of "the origin of life" and "protein crystal growth," observing molecular communication. Molecular communication becomes apparent when molecules are subjected to some kind of environmental change. When molecules are unable to cope with the environmental change (non-equilibrium state), we can expect to see them cooperate to create new methods or materials in an attempt to circumvent the situation. In my research on "the origin of life," I am attempting to recreate the environment of the primitive Earth in a laboratory and reproduce the process by which amino acids evolve into proteins. Here, I aim to create a mechanism in which molecules acquire the energy they need for their own evolution, triggered by fluctuations in environmental temperature. This could be called the molecular engine.

Our research on "protein crystal growth" aims to create better single crystals of proteins. This is necessary for X-ray structural analysis of protein molecules. Crystal growth is a phenomenon that creates a single order in an environment where countless molecules are constantly changing. We are attempting to directly observe the intermolecular communication that takes place here using fluorescence microscopy. We are also focusing on a certain protein present in the mitochondrial membrane and aiming for its crystallization and structural analysis.

Recent Books

• The hysteretic growth of microspherical particle consisting of thermal heterocomplex molecules from amino acids: Shigeru Sakurazawa, Hajime Honda, Eiichi Imai and Koichiro Matsuno: Viva Origino 22, pp 81-88, 1994
• Microcapsule formation in self-assembly of thermal heterocomplex molecules from amino acids: Shigeru Sakurazawa, Eiichi Imai, Hajime Honda and Koichiro Matsuno: Colloid & Polymer Science 274, pp 899-903, 1996
• Diffusion controlled formation of husk-like microcapsules: Shigeru Sakurazawa, Tsunayuki Ishimori, Hajime Honda and Koichiro Matsuno: Colloid & Polymer Science 275, pp 502-505, 1997
• Long-term relaxation and order formation phenomena in non-equilibrium dynamics of polymer electrolytes: Shigeru Sakurazawa: "Complex Systems 5" Workshop Report, pp 653-655, 1997.
• Orientation of protein crystals grown in a magnetic field: Shigeru Sakurazawa, Tomomi Kubota, Mitsuo Ataka: Journal of Crystal Growth 196, pp 325-331, 1999