Laboratory of Supramolecular Functional Chemistry
Graduate School of Science
Professor

Hiroyasu YAMAGUCHI

Assistant Professor Yuichiro KOBAYASHI

hiroyasu
kobayashiy11

URL: http://www.chem.sci.osaka-u.ac.jp/lab/yamaguchi/
Biological systems express
sophisticated and specific functions
through various (intra- andintermolecular) interactions. On theother hand, functional molecules havebeen developed in artificial systems thatare not found in biological systems. In
this laboratory, we aim to create
superior functional materials by
combining the advantages of bothbiomacromolecules (especiallymonoclonal antibodies) and artificial
polymers/low-molecular weight(Figure 1) Functionalization of monoclonal antibodies
molecules, as well as materials with newfunctions that have never been seen
Development of a sensor element that
before. Furthermore, we extract the
specifically detects a certain
structural essence of biomolecules atsubstance
the molecular level, and design andsynthesize alternative molecules andWe have prepared a monoclonal antibody thatpolymers. By creating materials thatbinds to acetone peroxide (TATP), an explosive,
specifically integrate these molecules,
by using a stable spirocyclic compound that has asimilar chemical structure to TATP as a hapten.
we aim to create novel functions.
When this antibody was used as a sensing
Creation of functionalized
element in a biosensor based on the surface
plasmon resonance method, TATP could be
antibodies
specifically detected (Fig. 2).
The aim is to create new functional

materials by introducing the excellent
functions of biological systems into artificialsystems.
Our research focuses on antibodies withspecificity. We have produced chemicallyhomogeneous "monoclonal antibodies" astailor-made proteins that bind to various
functional small molecules. Using theseantibodies, we have synthesized novel
supramolecular complexes, and byharmonizing antibodies with artificial
functional molecules, we have succeeded in
imparting functions that could not be
expressed by artificial molecules alone. Our
goal is to create sensing systems that utilize
the superior molecular recognition ability ofantibodies, and energy conversion andcatalytic systems that utilize the binding sitesof antibodies as specific reaction control
fields (Fig. 1).

Functionalization of artificial
materials incorporating biologicalcomponentsIn hemoglobin, peroxidase and cytochrome,
proteins form complexes with cofactors to
express functions such as oxygen transport,
redox enzymes and electron transfer,respectively. The coordination ofmetalloporphyrins, which are cofactors, withcertain amino acids in proteins plays animportant role. We have synthesizedhydrogels in which biogenic iron porphyrins
and amino acids (L-histidine) were introduced
into artificial polymers, and these hydrogels
self-assemble through coordination bonds toconstruct a pH-responsive material adhesion
system (Figure 3). More recently, we havealso been studying the control of the functionof cofactor-containing proteins by adheringand releasing hydrogels containing theproteins and cofactors, respectively.

(Figure 3) Self-aggregate formation between iron porphyringel (black-brown) and L-histidine gel (red staining)
If we can successfully hybridize

molecules derived from livingorganisms and synthetic molecules
used in artificial systems, we may

discover new functions that werepreviously unknown.

Experience a new world.

(Figure 2) Generation of monoclonal antibodies thatbind to TATP (the compound on the right is thestable compound used as the antigenic determinantof the immunogen)

Department of Biological Sciences
Graduate School of Science, Osaka University
1-1, Machikaneyama-cho, Toyonaka, Osaka
560-0043, Japan
TEL: +81-6-6850-5460
FAX : +81-6-6850-5457
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