Our
target : Molecular machine made of
protein
There
are many proteins in nature, which are principal components
of our lives, having high molecular recognition ability and
catalytic activity that are still
hard to artificially imitate.
However, from
the viewpoint of application, the natural protein does not
always have the optimum properties, where we think is the
real charm of protein engineering. This is why we are
trying to create various proteins by rational design and
molecular evolution technologies. Through the development
and utilization of suitable methods, we are expecting to
create proteins that can make stunt that native proteins
cannot. These will become an indispensable tool in the
research area called synthetic biology, which is getting
attention at present. In other words, our object is to
create a machine that normal engineers are making with
steel and plastics, with proteins! Also, our dream is not
making enjoyable toys but making gadgets (tools) that are
useful in real life.
Especially, we have been focusing on the development of a
new detection method (open-sandwich immunoassay,
OS-IA) based on the
antigen-dependent dimer formation of an antibody variable
domains (Fv = VH and VL). We proudly develop
OS-IA as a unique and
also useful detection (and selection) principle that no
other methods rely on. However, the stabilization of
proteins by its ligand is considered a general phenomenon,
and there is no wonder that the principle is generally
applicable to other binding proteins.
Including others, some of the themes in progress are
introduced as follows.
Current
research themes (excerpt)
・Novel
immunoassay approach based on the stabilization of an
antibody variable region (OS-IA)
-
Sensitive
noncompetitive detection system for small molecules such as
environmental pollutants and peptides
-
Integration
of
OS-IA with
microfluidics
-
Development of a selection method for high affinity
antibodies that is suitable for
OS-IA
-
Application to
intracellular protein modification detection
-
Molecular
evolution of proteins based on
OS principle
-
New
molecular imprinting technique using antibody
fragments
-
Novel
fluoroimmunoassay reagent
Q-body based on
antigen-dependent quench release
・Novel
nucleic acid sensor proteins
・Construction
methods for antibody-enzyme fusion proteins that does not
require gene manipulation
-
expression of
fusion proteins using trans-splicing
・Artificial
allosteric enzyme whose activity changes in response to
antigens
・Creation
of alkaline phosphatase that has higher activity and
thermostability than the wild-type enzyme
・Research
on bioluminescent enzymes
-
Analysis of
reaction mechanism of firefly luciferase
-
Novel molecular
interaction assay using functional complementation of
luciferase mutants
・Controlling
cellular functions by antibody-receptor chimera
(collaboration with Dr. Kawahara in Nagamune
Lab.)
・Recombinant
antibody expression using silkworm (collaboration with
Prof. Park in Shizuoka Univ.)