Laboratory of Pharmacokinetic Optimization
|Adjunct Project Leader||Kouhei Tsumoto|
|Project Researcher||Taisuke Nakayama
2. Background and objectives
We conduct investigation on the development of biologics and their optimization based on the combination of the following techniques: (i) analysis of antibodies originated from various animal species, (ii) engineering antibodies through phage display technology and rational design and (iii) control of stability of biologics through the analysis of solvation.
3. Overview of our research
Our study mainly focus on the analysis of basic characteristics of biological materials including antibodies. Through these studies, we aim to propose the functions and features required for next-generation biologics. Our study also cover the basic technologies for the optimization of biological materials. Below are the examples:
3-1. Basics of the molecular recognition of biological materials
Interactions of biopolymers are based on the specific recognition of the partner by the use of hydrogen bonds, van der Waals force, etc. We adopt antibodies as the example to investigate on the mechanism of the specific recognition through structural biology and physicochemical analysis. By targeted mutagenesis and modeling, the roles of each amino acid residues in precise molecular recognition is revealed.
- Akiba H, Tsumoto K. : Thermodynamics of antibody-antigen interaction revealed by mutation analysis of antibody variable regions., J. Biochem, 158:1-13, 2015
- Kudo S, Caaveiro JM, Nagatoishi S, Miyafusa T, Matsuura T, Sudou Y, Tsumoto K. : Disruption of cell adhesion by an antibody targeting the cell-adhesive intermediate (X-dimer) of human P-cadherin, Sci Rep., 7:39518, 2017
- Kiyoshi M, Caaveiro JM, Kawai T, Tashiro S, Ide T, Asaoka Y, Hatayama K, Tsumoto K. : Structural basis for binding of human IgG1 to its high-affinity human receptor FcγRI., Nat Commun., 6:6866, 2015
- Nakayama T, Mizohata E, Yamashita T, Nagatoishi S, Nakakido M, Iwanari H, Mochizuki Y, Kado Y, Yokota Y, Satoh R, Tsumoto K, Fujitani H, Kodama T, Hamakubo T, Inoue T. : Structural features of interfacial tyrosine residue in ROBO1 fibronectin domain-antibody complex: Crystallographic, thermodynamic, and molecular dynamic analyses., Protein Sci., 24(3):328-40, 2015
3-2. Engineering biological materials: modification
Targeting ligands including antibodies require specific and tight interaction with their respective targets. We utilize the knowledge obtained through basics to investigate on the improvement of the binding functions of the ligands by adopting phage display and simulation in silico.
- Kiyoshi M, Caaveiro JM, Miura E, Nagatoishi S, Nakakido M, Soga S, Shirai H, Kawabata S, Tsumoto K. : Affinity improvement of a therapeutic antibody by structure-based computational design: generation of electrostatic interactions in the transition state stabilizes the antibody-antigen complex., PLoS One, 27;9(1):e87099, 2014
- Fukunaga A, Tsumoto K. : Improving the affinity of an antibody for its antigen via long-range electrostatic interactions., Protein Eng Des Sel., 26(12):773-80, 2013
3-3. Engineering biological materials: functionalization
Functionalization of biological materials are conducted through the fusion of another targeting ligand to the targeting molecules such as antibodies. We investigate on the construction of the techniques to develop and analyze bispecific antibodies as well as materials for drug delivery.
- Yumura K, Akiba H, Nagatoishi S, Kusano-Arai O, Iwanari H, Hamakubo T, Tsumoto K. : Use of SpyTag/SpyCatcher to construct bispecific antibodies that target two epitopes of a single antigen, J. Biochem., in press, 2017
- Perche F, Uchida S, Akiba H, Lin CY, Ikegami M, Dirisala A, Nakashima T, Itaka K, Tsumoto K, Kataoka K. : Improved brain expression of anti-amyloid β scFv by complexation of mRNA including a secretion sequence with PEG-based block catiomer, Curr Alzheimer Res., in press, 2016
3-4．Physical properties of biological materials
For the production, purification, and storage of biological materials, understanding of the solution stability of the molecules is required. We apply various analytical methods to investigate on the functions of solvents and additives for the thermostability and aggregation propensity. Factors to control these properties are investigated through the analyses, which lead to the development of analytical or purification methods as well as compounds to control solvation.
- Ota C, Noguchi S, Nagatoishi S, Tsumoto K. : Assessment of the Protein-Protein Interactions in a Highly Concentrated Antibody Solution by Using Raman Spectroscopy., Pharm Res., 33(4):956-69, 2016
- Totoki S, Yamamoto G, Tsumoto K, Uchiyama S, Fukui K. : Quantitative laser diffraction method for the assessment of protein subvisible particles. J Pharm Sci., 104(2):618-26, 2015
- Ito T, Tsumoto K. : Effects of subclass change on the structural stability of chimeric, humanized, and human antibodies under thermal stress., Protein Sci., 22(11):1542-51, 2013