is a Japanese scientist, a professor at

Waseda University Waseda University (Japanese: ), abbreviated as or , is a private university, private research university in Shinjuku, Tokyo. Founded in 1882 as the Tōkyō Professional School by Ōkuma Shigenobu, the fifth Prime Minister of Japan, prime ministe ...

department of

science Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...

and

engineering physics Engineering physics (EP), sometimes engineering science, is the field of study combining pure science disciplines (such as physics, mathematics, chemistry or biology) and engineering disciplines (computer, nuclear, electrical, aerospace, medic ...

course. His specialty is

biophysics Biophysics is an interdisciplinary science that applies approaches and methods traditionally used in physics to study biological phenomena. Biophysics covers all scales of biological organization, from molecular to organismic and populations ...

, particularly the mechanism of

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

s and

motor protein Motor proteins are a class of molecular motors that can move along the cytoskeleton of cells. They do this by converting chemical energy into mechanical work by the hydrolysis of ATP. Cellular functions Motor proteins are the driving force b ...

s. Since spectroscopic techniques for studying proteins yielded only averaged characteristics of an ensemble of proteins, he constructed his own research method. He focused on his long-held interest in

striated muscle Striated muscle tissue is a muscle tissue that features repeating functional units called sarcomeres. Under the microscope, sarcomeres are visible along muscle fibers, giving a striated appearance to the tissue. The two types of striated muscle a ...

— “how a beautiful structure is self-organized, and how it is related to force-generating function.” Then he tackled the reconstitution of the structure and function of the thin (

actin Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of ...

) filaments in striated muscle, especially cardiac muscle, then to defining the mechanism of Spontaneous Oscillatory Contraction (SPOC) of striated muscle that occurs at intermediate activation conditions between full activation and relaxation. It was an important breakthrough regarding a phenomenon that had been “almost completely ignored,” he says. Ishiwata's research interests go beyond the mechanical and physiological import of SPOC to bio-motile systems focusing on the structural and functional hierarchy from single molecules (

myosin Myosins () are a Protein family, family of motor proteins (though most often protein complexes) best known for their roles in muscle contraction and in a wide range of other motility processes in eukaryotes. They are adenosine triphosphate, ATP- ...

kinesin A kinesin is a protein complex belonging to a class of motor proteins found in eukaryotic cells. Kinesins move along microtubule (MT) filaments and are powered by the hydrolysis of adenosine triphosphate (ATP) (thus kinesins are ATPases, a typ ...

) to

macromolecular assemblies In molecular biology, the term macromolecular assembly (MA) refers to massive chemical structures such as viruses and non-biologic nanoparticles, cellular organelles and cell membrane, membranes and ribosomes, etc. that are complex mixtures of p ...

(

myofibrils A myofibril (also known as a muscle fibril or sarcostyle) is a basic rod-like organelle of a muscle cell. Skeletal muscles are composed of long, tubular cells known as muscle fibers, and these cells contain many chains of myofibrils. Each myofibr ...

, meiotic spindle and cells (

cardiac The heart is a muscular organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrients to the tissu ...

HeLa HeLa () is an immortalized cell line used in scientific research. It is the oldest human cell line and one of the most commonly used. HeLa cells are durable and prolific, allowing for extensive applications in scientific study. The line is ...

, etc.). He expects that the multiplex network of Chemo-Mechanical Feedback (CMF) loops exist over various hierarchical levels. He proposes that the heart is a typical organ in which nano and macro, i.e., mechano-chemical functions of molecular motors and heartbeat, are directly coupled to each other through the CMF loops.

References

Ishiwata, Shin'ichi Year of birth missing (living people) {{Japan-scientist-stub