Yuki Yanagida

biophysics
structural biochemistry

1) Elucidation of the mechanism of protein secondary structure (alpha helix) folding
2) Development of a drug delivery system using the spherical protein ferritin​

1. Proteins are formed when polypeptide chains, consisting of 20 different amino acids linked together in various orders and lengths, fold to acquire their unique function and three-dimensional structure (tertiary structure). The secondary structure of a protein is a locally stabilized structure found within the tertiary structure, and one representative example is the helical structure called the α-helix. Although the α-helix is a very stable structure, its formation mechanism is not fully understood, and it remains difficult to predict the presence of the α-helix physicochemically from the amino acid sequence of a protein. In this research, we aim to discover new helix stabilizing factors and incorporate and develop existing theories by investigating and comparing the structures of a model peptide and its variants using NMR and CD.
2. In recent years, drug delivery systems (DDS), a technology that delivers the necessary amount of drug only to the necessary location, have attracted attention. Among these, research into applying nanoparticles to DDS is particularly active. Ferritin is an iron-storage protein found in almost all living organisms. Ferritin has a 24-mer spherical structure formed by the aggregation of 24 proteins, and its interior is hollow to store iron. Ferritin in E. coli and other bacteria dissociates into dimers in an acidic environment and reassembles into a 24-mer when returned to a neutral state. By utilizing this property, it is possible to load drugs into the interior of ferritin. Furthermore, it has been shown that ferritin specifically binds to transferrin receptor 1 (TfR1) and is taken up into cells, and TfR1 is known to be overexpressed in cancer cells. Therefore, ferritin is expected to have a targeting effect on cancer cells. However, human ferritin has the problem that its structure breaks down after dissociation under acidic conditions and does not reassemble into a 24-mer even when returned to a neutral state. Therefore, we are creating and testing various mutants to improve the stability of human ferritin.

Chemistry experiment

2020 Soka University Faculty of Science and Engineering Department of Science and Engineering for Sustainable Innovation Graduated
2022 Soka University Graduate School of Science and Engineering Biosciences Major Master Course , Completed
2025 Soka University Graduate School of Science and Engineering Biosciences Major Doctoral Course , Doctor of Science Completion
2025 Soka University Faculty of Science and Engineering Assistant Professor

Japan Protein Science Society
Biophysical Society of Japan
Japan Society for Nuclear Magnetic Resonance
Japanese Biochemical Society

Yuuki Yanagida, Kiyomi Yoshida, Mio Ohtomo, Kazuo Fujiwara and Masamichi Ikeguchi.
Mechanisms of helix induction by the closed loop.
Protein science. Vol.34, Issue 6, e70171, 2025.