Fiscal Year 2017, Tokyo Institute of Technology ASPIRE League Research Grant
Selected Research Project for Type 1 in FY2017
NamePrincipal
Researcher

School atTokyo Tech
Position
HKUST
KAIST

Co-researchers

Takafumi Ueno
School of Life Science and TechnologyProfessor
ZHU Guang, Professor
Division of Life Science
Yoon Sung Nam, Associate Professor
Department of Materials Science & Engineering,
Sierin LIM, Associate Professor

NTU

School of Chemical and Biomedical Engineering,
Kelin Xia, Assistant Professor
School of Physical & Mathematical Sciences,

Tsinghua

Diannan Lu, Associate Professor
Department of Chemical Engineering
Functional Design of Protein Cage for Sustainable

Subject of the research project

Bio-nanomaterial

Protein assemblies have recently become recognized as
potential molecular scaffolds for applications in materials
science and bio-nanotechnology. Efforts to design protein
assemblies for construction of protein-based hybridmaterials
Summary of the research projectwithmetalions,

metal

complexes,andnanomaterials now indicate a growing field with acommon aim of providing novel functions and mimicking
natural functions. However, the important roles of protein
assemblies in sustainable materials science have not beensystematically investigated and established.
Protein cage is one of the most useful scaffolds amongprotein assemblies with nano-sized structures, such as
tube, wire, and two-dimensional array, because the cage
has a various range of diameter from several to hundreds
nm, and can be conjugated with natural and synthetic
functional molecules on both the inside and outside
surfaces. Many researchers reported functionalization ofprotein cages for the broad range of applications andimplications focusing on the medical and biotechnology
sectors. However, there is a limitation on development ofdrug delivery and imaging reagent due to low stability to
conjugate

variouscompositesinvolving

inorganic

materials. Thus, highly robust protein cages are required
to encapsulate and display inorganic materials withbionano functions, such as drug delivery and imaging.
We therefore propose to design and construct new typesof sustainable protein cages conjugated with inorganic
compounds for medical and bionano-applications. Ferritin(Fr), which plays the role of an iron storage protein, isknown to accommodate various metal ions/complexes andis suitable for catalytic reactions conducted in an aqueous
medium. From a protein engineering point of view, theeffective preparation, yield, and stability make the Fr
cagesuitableforuseasmolecular

templates

toaccumulate metal ions, complexes, and nanoparticles forconstruction of sustainable biomaterials to deliver metal
drug and metal imaging reagents, such as gold and silver
nanoparticles, and gadolinium complexes, into living cells.
The accumulation of the inorganic compounds with

desired size, number and position in the Fr cage isrequired for the accurate functions
cell.

promoted in living

Thus, in the research project, we pursue thefollowing objectives to establish the new research field ofsustainable bio-nanomaterials :Summary of the research project(1) Computational design of the Fr cage(2) Incorporation and preparation of inorganic materials
in the Fr cage and surface modification of the composite(3) Evaluation of the functions toward medicinal andbiomaterial applications
Many metal complexes and inorganic compounds are
known to show biomedical functions, yet at the same time,they have some issues, such as less solubility, instability,and high cytotoxicity, etc.

Encapsulation of them into

biocompatible materials is one of the solutions on thebasis of accurate design of the scaffold at the atomic level.
The Fr cage meets all the requirements because of its
high robustness and many available crystal structures.
Eventually, we would like to optimize the cage responsible
for the functional materials to expand the new research
field of bio-nanotechnology.
The principal investigator will first conduct this projectwith organization of a interdisciplinary research groupcomposed of computational, synthetic, material, andbiological scientists from the ASPIRE league.