Life Science and Technology News
Peptide Engineering & Chemical Biology
The Department has a variety of laboratories for Life Science and Technology, in which cutting-edge innovative research is being undertaken not only in basic science and engineering but also in the areas of medicine, pharmacy, agriculture, and multidisciplinary sciences.
This "Spotlight" series features a laboratory from the Department and introduces you to the laboratory's research projects and outcomes. This time we focus on Mihara and Tsutsumi Laboratory.
*March 31, 2024:Professor Mihara retired from Tokyo Tech.
Areas of Supervision
Primary/Life Science and Technology
Professor Hisakazu Mihara and Associate Professor Hiroshi Tsutsumi
Degree | Professor Hisakazu Mihara : Dr.Sc. 1986, Kyushu University Associate Professor Hiroshi Tsutsumi : PhD 2004, Tokyo Institute of Technology |
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Areas of Research | Professor Hisakazu Mihara : Bioorganic Chemistry, Chemical Biology, Peptide Engineering Associate Professor Hiroshi Tsutsumi : Chemical Biology, Supramolecular Chemistry, Peptide Chemistry |
Keywords | Professor Hisakazu Mihara : Designed Peptide, Peptide Biochip, Self-Assembling Peptide, Biomaterial for Cell, Peptide Phage Display Associate Professor Hiroshi Tsutsumi : Peptide, Hydrogel, Phage Display, Bioimaging |
Website | Mihara Laboratory![]() |
We design various functional peptides with characteristic structures such as α-helix and β-sheet. Main three projects are "Hydrogel materials as a scaffold for cell proliferation and differentiation", "Cell penetrating peptides (CPP) for selective drug delivery" and "Peptide ligands for detection of lectin proteins associated with virus/bacteria infection to cells".
Peptides that spontaneously assemble into various and precise structures have been designed using electrostatic interaction, hydrophobic interaction and hydrogen bond formation. We have designed a self-assembling peptide E1Y9 that can assemble into nanofibers with a β-sheet structure in aqueous solution (Fig. 1). E1Y9 can form hydrogels in response to calcium ion (Ca2+). E1Y9 hydrogels have similar properties to natural hydrogels like collagen and give suitable environments for cell proliferation. Therefore, E1Y9 hydrogels are expected to be good biomaterials for cell culture and regenerative medicine. For example, E1Y9 hydrogel with string shape is useful for the culture and differentiation control of neuronal cells (Fig. 1). Culture and differentiation control of various cells such as osteoblast cells and stem cells have been performed using E1Y9 hydrogels.
Recently, various peptides with cell penetrating activity have been designed. We designed an amphiphilic α-helix peptide library by systematic replacement of amino acids, and found various cell penetrating peptides (CPPs) from our library (Fig. 2). In particular, selective CPPs to cancer cells are found and expected to be a useful drug delivery tool. We combined cancer cell selective CPP and gold nanoparticles (GNPs) to produce hybrid materials for drug delivery. CPP-GNPs with anticancer drug showed selective anticancer activity corresponding to cell penetrating activity of α-helix peptides. In addition, we are screening CPPs with further cancer cell penetrating activity and selectivity by the detail analysis of cell penetrating activity.
Lectins are carbohydrate-binding proteins and recognize mono/oligosaccharides with high selectivity. As various lectins and glycoconjugates such as glycoproteins and glycolipids are found on the cell surface, the lectin-glycoconjugate interaction is associated with various life events including cell-cell interactions, pathogen (virus) infection and tumor metastasis. Therefore, the selective detection of lectins and glycoconjugates is important to disclose the complex biological processes mediated by lectins. We designed a glycopeptide platform as a new candidate to produce various lectin ligands. Combination of a sugar unit with various peptide sequences will give useful ligands comparable to native glycans. We designed and constructed glycopeptide libraries using a genetic engineering method and a chemical modification method, and found useful glycopeptide ligands with high binding affinity and selectivity (Fig. 3). In addition, we developed optical lectin detection probes by combining glycopeptide ligands with gold nanoparticles (Fig. 3).
Contact
Professor Hisakazu Mihara
Room 801, B1 building, Suzukakedai campus
Email hmihara@bio.titech.ac.jp
Associate Professor Hiroshi Tsutsumi
Room 802, B1 building, Suzukakedai campus
Email htsutsum@bio.titech.ac.jp
*Find more about the lab and the latest activities at the lab site (Japanese).
*May 1, 2025:Some of the content has been updated with the latest information.