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Laboratories

The Department of Macromolecular Science comprises three core laboratories and one cooperative laboratory, with each laboratory comprising several research groups. Click on a laboratory name for more details.

Macromolecular Synthesis & Reactions

Polymer Reaction Chemistry, Macromolecular Precise Science,
Polymer Synthesis Chemistry,

Polymer Reaction Chemistry
Kiyotaka ONITSUKA (Professor), Taka-aki OKAMURA (Associate Professor),
Naoya KANBAYASHI (Assistant Professor)

Our research involves the development of new polymer synthesis and functionalization incorporating a characteristic feature of metal elements. For example, precise design of new transition metal complexes and investigation of their reactivity lead to the development of new polymerization catalysts. Functionalization of polymers based on the control of molecular structure is investigated by using the methodology of organic synthesis. Our research interest is also focused on metalloenzyme. Model complexes of active sites and non-natural peptide are designed and structurally characterized.

1. Development of new organometallic polymerization catalysts and their application to synthesis of functional polymers
2. Functional macromolecular complexes composed of organometallic units
3. Investigation of the reactivity controlling mechanism in the active center of metalloenzyme using model complexes having simple ligands and/or short peptides.
4. Synthesis of non-natural amino acid polymers for higher order structure formation and expression of novel functions.
5. Sequence and function analyses of proteins and protein complexes using novel metal complex sequencing reagents.

Home Page: https://www.chem.sci.osaka-u.ac.jp/lab/onitsuka/e

Macromolecular Precise Science
Akihito HASHIDZUME (Professor), Masaki NAKAHATA (Assistant Professor)

Macromolecular substances are ubiquitous, and these substances enrich our lives. Our bodies are also composed of macromolecules, e.g., nucleic acids and proteins. To unravel the reasons behind why life has chosen macromolecules as essential building blocks, and to elucidate the crucial roles that macromolecules play in our life, we devote our efforts to understand the nature of macromolecules, i.e., macromolecularity. We also aim at the creation of high-performance macromolecules based on macromolecularity. We are carrying out three projects as follows:

(1) We synthesize precise macromolecules with well-defined chemical structures because these precise macromolecules are critical for deeper understanding of macromolecularity.
(2) We strive to understand macromolecularity utilizing the precise macromolecules.
(3) We challenge existing boundaries to creation of high-performance macromolecules comparative to biological macromolecules using the precise macromolecules.

Home Page: https://www.chem.sci.osaka-u.ac.jp/lab/hashidzume/index_eng.html

Polymer Synthesis Chemistry
Arihiro KANAZAWA (Associate Professor)

Recently, well-designed stimuli-responsive polymers have attracted much interest as precursors of advanced polymer materials such as nano-organized self-assemblies, intelligent hydrogels, and DDS. In particular, recent progress in living polymerization has encouraged us to design various types of block copolymers in order to examine their stimuli-induced self-association. We have prepared a variety of functional polymers with well-controlled structures and molecular weights by living cationic polymerization in the presence of an added base. On the basis of these results, we have designed a new strategy for preparing block copolymers with various types of stimuli-responsive properties such as thermosensitive physical gelation.

1. Syntheses of well-defined polymers with various characteristic properties by living cationic polymerization.
2. Syntheses of advanced stimuli-responsive block copolymers.
3. Investigation of polymerization mechanism and design of novel living polymerization.


Concept of macromolecular design and living polymerization
for syntheses of well-designed stimuli-responsive polymers

Home Page: https://www.chem.sci.osaka-u.ac.jp/lab/aoshima/e_index.html

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Macromolecular Structure, Properties, and Functions

Polymer Physical Chemistry, Polymeric Materials Design

Polymer Physical Chemistry
Tadashi INOUE (Professor), Osamu URAKAWA (Associate Professor)

1. Shear induced structures of soft matters.
2. Nonlinear rheology and rheo-optics of polymer solids.
3. Molecular motions of hyper-branched polymers.
4. Structure and molecular motions of supramolecules.
5. Hydration and molecular motions of water-soluble polymers
6. Structure and dynamics of polymer composites.

Soft matter stands for soft materials including polymers, liquid crystals, suspensions, and self-assembling molecules which form a large mesoscopic structure much larger than atoms. Soft matters are “soft” and therefore they can easily respond to external fields like strain fields, flow fields, electric fields and so on, and sometimes show drastic structural changes. We have been studying their unique physicochemical properties, particularly nonlinear responses under strong external fields, in addition to their fruitful equilibrium properties and dynamics. Our research is focused on molecular interpretation of rheological phenomena of polymers and micelles as a model system of soft matter.

Home Page: https://www.chem.sci.osaka-u.ac.jp/lab/inoue/index_e.html

Polymeric Materials Design
Yoshinori TAKASHIMA (Professor)

In the realm of polymer material design, various applications exist such as adhesives, stimuli-responsive materials, and materials with specific mechanical properties, reflecting a diverse array of required functionalities. Traditional molecular designs have limitations in meeting all these functional demands, necessitating new approaches in molecular and material design. Our laboratory explores novel polymer materials aiming to create new 'joy' and 'value' by leveraging both non-covalent and covalent bonds. By employing reversible bonds and movable cross-linkages as illustrated, we extend applications to actuators, molecular adhesives, self-repairing materials, molecular recognition materials, and biomaterials.

Home Page: https://www.chem.sci.osaka-u.ac.jp/lab/takashima/en/

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Macromolecular Assemblies

Macromolecular Structure,
Supramolecular Science, Polymer Functional Chemistry
Macromolecular Solutions

Macromolecular Structure
Katsumi IMADA (Professor), Tatsuya KAWAGUCHI (Associate Professor (Lecturer)), Norihiro TAKEKAWA (Assistant Professor)

Biological process is driven by complex molecular machines composed of biological macromolecules. The flagellum, which is an organelle for bacterial motility, is one of those molecular machines. The flagellum is a huge protein assembly composed of a helical filamentous screw, a molecular universal joint, a highly efficient ion-driven motor and a protein export apparatus for self-construction. The Laboratory of Macromolecular Structure aims to proved fundamental understanding of operating principles and the self-assembly mechanism of biological macromolecular machines, such as the bacterial flagellum, through the studies of molecular structure at atomic resolution and reconstitution of the molecular machines. We also study structures of polymer complexes with low molecular weight compounds and the relationship between their structures and functions.

1.Rotational mechanism of the bacterial flagellar motor.
2. Self-assembly mechanism of the bacterial flagellar motor.
3. Structural and functional studies on bacterial protein secretion systems.
4. Structural and functional studies on environmental sensing units of bacteria.
5. Study on the structure of polymer complex with small molecule and its formation mechanism.


The flagellar type III export apparatus and F/V-type ATPases share a common architecture.

Home Page: https://www.chem.sci.osaka-u.ac.jp/lab/imada/en/

Supramolecular Science, Polymer Functional Chemistry
Hiroyasu YAMAGUCHI (Professor), Yuichiro KOBAYASHI (Assistant Professor)

In biological systems, life process is led by the unique behavior of macromolecules such as proteins and DNA. Molecular recognition by macromolecules plays an important role, for example, in substrate specificity of enzymes and antigen-antibody reactions in human life. Selective molecular recognition among macromolecules is achieved through a large number of weak interactions. We have focused our attention on the special behavior of antibodies, especially monoclonal antibodies, because they can recognize a larger and more complicated compound with high specificity than that can synthetic host molecules or enzymes.
In this laboratory, we develop novel materials through hybridization of bio-related macromolecules such as monoclonal antibodies with artificial/synthetic small molecules. We construct functionalized catalytic and energy conversion systems based on specific molecular recognition of biomacromolecules and selective assembly of bio/synthetic molecules.

Home Page: https://www.chem.sci.osaka-u.ac.jp/lab/yamaguchi/english/

Macromolecular Solutions
Ken TERAO (Professor), Rintaro TAKAHASHI (Associate Professor)

Macromolecules in solution can take a nearly infinite number of conformations due to their high degree of freedom of internal rotations. Macromolecules in solution have, therefore, specific characteristics not found in small molecules. Intramolecular interactions in a macromolecule and intermolecular interactions with solvent molecules significantly influence the molecular shape in solution. Furthermore, strong intramolecular interactions, including hydrogen bonding and electrostatic interactions, lead to the formation of micelles and aggregates. The intermolecular interactions between polymers through solvents can also cause various phase separations. Such phenomena correlate with the functions in biosystems. Our research aim is to clarify the various phenomena exhibited by macromolecules in solution, that is, single chain conformation, complex formation behavior, and phase separation behavior by using the latest scattering and spectroscopic methods.

1 Conformation and molecular recognition ability of polysaccharides and their derivatives
2 Molecular conformation and intermolecular interactions of ring and branched polymers
3 Aggregation and phase separation of branched polymers-poor solvent systems
4 Complex formation of polymers with nanoparticles

Home Page: https://www.chem.sci.osaka-u.ac.jp/lab/terao/

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Informative Polymer Science (Institute for Protein Research)

CryoEM Structural Biology, Protein Crystallography, Supramolecular Crystallography

CryoEM Structural Biology
Takayuki KATO (Professor), Hiroko TAKAZAKI (Assistant Professor),
Mao OIDE (Assistant Professor)

Proteins, which underpin the fundamental processes of life, are polymers composed of amino acids linked together in chains, forming three-dimensional structures programmed by their sequences. The three-dimensional structure of a protein is closely related to its function, and disruption of this structure results in loss of function. Therefore, the three-dimensional information of proteins is crucial foundational knowledge not only in life sciences but particularly in the field of medicine, especially for drug discovery. We analyze the three-dimensional structure of molecular motors using cryo-electron microscopy, elucidating how proteins convert chemical energy into mechanical energy through structural changes in solution. Additionally, we are developing methods for high-resolution analysis using cryo-electron microscopy and for preparing samples for structural analysis.

1. Elucidation of the energy conversion mechanism of rotary molecular motors
2. Development of methods to analyze structural changes of biomolecules in solution
3. Understanding the structure and function of receptor proteins
4. Development of high-resolution structural analysis methods using cryo-electron microscopy
5. Development of sample preparation methods for structural analysis using cryo-electron microscopy


The 1.53Å resolution structure of apoferritin

Home Page: http://www.protein.osaka-u.ac.jp/cryoem/index2.html

Protein Crystallography
Genji KURISU (Professor), Akihiro KAWAMOTO (Associate Professor)

1. Structural studies of photosynthetic energy-transducing membrane protein complex and related redox enzymes
2. Crystal structure analyses of dynein motor
3. High resolution structural analysis of rat liver vault

Three-dimensional protein structure brings us a deeper insight into the biological function. X-ray crystallography is the best method to determine atomic coordinates of protein molecules. The main aim of our group is the X-ray structure determination of the biological macromolecular assemblies including membrane protein complexes, in order to elucidate the molecular mechanism of the highly organized biological processes at atomic level.


Crystal Structure of the dynein motor domain

Home Page: http://www.protein.osaka-u.ac.jp/crystallography/LabHP/en/

Supramolecular Crystallography
Atsushi NAKAGAWA (Professor), Eiki YAMASHITA (Associate Professor),
Makoto MATSUDA (Assistant Professor)

1. Operating a synchrotron beamline for biological macromolecular assemblies at SPring-8.
2. Developing a new crystallographic techniques for structure determination of biological macromolecular assemblies.
3. Structural studies of biological macromolecules and biological macromolecular assemblies.
4. Structural studies on proteins working in brain and nervous system.

Macromolecule assemblies, consisting of proteins, nucleic acids, and other substances, play key roles in all living system. Our laboratory works on structure determination of biological macromolecular assemblies using X-ray diffraction technique. Development of tools for X-ray crystallography of biological macromolecular assemblies, including the synchrotron radiation beamline at SPring-8, is also one of our main works.

Home Page: http://www.protein.osaka-u.ac.jp/rcsfp/supracryst/index.html

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Department for the Administration of Safety and Hygiene

Chemistry for Environment and Safety
Hitoshi YAMAMOTO (Professor), Masaomi TAKAHASHI (Associate Professor)

1. Development of low barrier ion conductive polymer electrolytes.
2. Development of the photo-switching functional molecules.
3. Development of detection methods for environmental chemicals.
4. Construction of education system for realization of safety concious culture in the university.
5. Research and analyses of university accidents in the world.
This laboratory belongs to the department for the administration of safety and hygiene, whose mission is managing safety and hygiene of all people constituting the university. The research in this laboratory aims to contribute to the safety of wide area in science and technology. At present, our research projects focus on development of new functional molecules such as low barrier ion conductive polymers for the safety of Li ion batteries, photo-switchable hydrogen bonds for environmental chemistry, etc. In addition, our laboratory proposes safe methods and techniques for conducting research and experiments through investigation and analyses of university accidents in the world.

Home Page: https://www.dash.osaka-u.ac.jp/lab/