Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Keitaro Suyama Last modified date:2018.07.24

Assistant Professor / Laboratory of Molecular Biochamistry / Division for Experimental Natural Science / Faculty of Arts and Science

1. The elastin-derived synthetic peptide analogs (FPGVG)n and (WPGVG)n, containing aromatic amino acids, demonstrate temperature-dependent self-association (coacervation). In this study, we prepared cyclic analogs of these elastin-derived peptides to investigate the molecular mechanism of coacervation and to obtain potent coacervatable peptides. It was revealed that cyclized elastin-derived peptide analogs, namely cyclic (FPGVG)n with n = 3–5, exhibited coacervation at a significantly lower concentration (1.0 mg/ml) than did linear (FPGVG)5 (requiring 30 mg/ml to show coacervation). Our results from molecular dynamics simulations suggest that local turn structures are important for coacervation of elastin-derived cyclic peptide analogs. In addition, our results from microscopy and dynamic light scattering measurements of cyclic (FPGVG)5 aqueous solutions indicate that this peptide can form liposome-like aggregate structures approximately 3 µm in diameter..
2. Self-assembly properties and structural analyses of fluorescent-labeled analogs of elastin-derived synthetic peptide (FPGVG)5.
3. Coacervation and fluorescence properties of fluorescent-labeled elastin-derived peptides.
4. 田坪大来, 巣山 慶太郎, 野瀬 健, Fluorescence Analysis Using a Molecular Probe 1,8-ANS for Elucidation of the Molecular Mechanisms Underlying Coacervation of a Tryptophan-containing Elastin derived Dimeric Peptide, 第52回ペプチド討論会, 2015.11.
5. 巣山 慶太郎, 田坪大来, 袈裟丸 仁志, 野瀬 健, Coacervation Properties and Structural Analysis of Aminobenzoyl-labeled Fluorescent Elastin-derived Peptides, 第52回ペプチド討論会, 2015.11, Biological reactions within living cells are affected by temperature. Therefore, mapping the intracellular temperature of living cells is expected to contribute to an improved understanding of cellular events and the establishment of novel therapeutics. Previously, Uchiyama et al. demonstrated intracellular temperature mapping based on a fluorescent polymeric thermometer consisting mainly of acrylamide derivatives. Elastin-derived peptides exhibit reversible self-association (coacervation) under physiological conditions. Therefore, it was considered that these peptides might serve as useful materials for the development of such a fluorescent thermometer. Recently, we reported that the short synthetic elastin-derived peptide (FPGVG)5 demonstrates coacervation, which suggests that fluorescent-labeled (FPGVG)5 peptides, in particular, may be useful as basic materials for developing a novel fluorescent peptide-based thermometer. In the present study, we synthesized fluorescent-labeled analogs of (FPGVG)5 and investigated their coacervation property and peptide conformation..
6. 巣山 慶太郎, 野瀬 健, 谷口 卓, 前田衣織, 河野敬一, エラスチン由来ペプチドダイマーの自己集合特性および立体構造の解析, 分子・物質合成PF H25年度シンポジウム , 2014.03.
7. 巣山 慶太郎, 谷口 卓, 前田衣織, 田坪大来, 野瀬 健, Coacervation Property and Secondary Structure of Synthetic Dimer Peptides of the Elastin-derived Pentapeptide Repeat-related Peptide, 4th Asia-Pacific International Peptide symposium 2013/50th Japanese Peptide Symposium , 2013.11, Elastin is the core protein of elastic fibers in the elastic tissues plays an essential role in tissue biomechanics, providing the extensibility and condensability. Elastin shows coacervation (reversible association/dissociation phenomena) under physiological conditions. Tropoelastin, the precursor protein of elastin, contains characteristic repetitive sequences such as the pentapeptide sequence, Val-Pro-Gly-Val-Gly (VPGVG), in its hydrophobic regions. However, it was reported that large molecular size was needed for coacervation of elastin-derived peptide (VPGVG)n (numbers of repetition: n>40). Recently, we reported that synthetic hydrophobic oligomers (IPGVG)n and (FPGVG)n demonstrate coacervation at significantly smaller repetition numbers (n=5~7). Because of their low molecular size, these analogs are expected to be useful as model peptides for structure analysis and base materials for developing various biomedical products. In this study, to obtain more short coacervatable peptides, we synthesized dimers of pentapeptide (FPGVG)5 and investigated their coacervation property and secondary structures..
8. Keitaro Suyama, Kazuhiro Matsumoto, Tsutomu Katsuki, Asymmetric Lewis Acid Catalysis of Aluminum(salalen) Complexes: Friedel-Crafts Reaction of Indole, 19th Joint Seminar of the Busan Branch of the Korean Chemical Society and the Kyushu Branch of the Chemical Society of Japan, 2009.05.