Hiroshi Yamaguchi

Major research fields

Protein Crystallography, Protein Science

Proteins or protein assemblies play important roles in various biological systems. In most of them, three-dimensional structures are essential for exerting their biological functions. The protein structures give us a deeply understanding of architectures, chemical reactions, biological functions, and properties of proteins. An X-ray diffraction method is the only method for determining three dimensional protein structures at the atomic resolution without limitation of their molecular weight. An X-ray small angle scattering method is complementarily important for analyzing low resolution structures and structure changes of proteins in solution.

Our aims are to elucidate the three-dimensional protein structure by using these X-ray techniques, to analyze the structure-function relationships and structure-property relationships, and to establish their general principles for protein structure. These knowledge not only gives us basic chemical and biological information, but also allow us to have the advanced application of proteins such as industrial and medical applications of proteins and their structures. In addition, we also focused on analysis of protein folding mechanism in order to understand the rules of folded protein architectures.

Our research interests include the process of protein maturation including folding and posttranslational modification and the process of protein reaction. For these purposes, we are trying to solve the structures of mature forms, intermediates, and complexes with their ligands both in crystalline state and in solution. Our target molecules are several proteins of important biological systems including enzymes, peptide hormones and amyloid precursor proteins.

Major relevant publications

1. M. Kataoka, H. Oya, A. Tominaga, M. Otsu, T. Okajima, K. Tanizawa and H.Yamaguchi. Detection of the reaction intermediates catalyzed by a copper amine oxidase. J. Synchrotron Rad. (2011), 18, 58-61.
2. M. Okumura, M. Saiki, H. Yamaguchi, and Y. Hidaka. Acceleration of Disulfide-Coupled Protein Folding Using Glutathione Derivatives. FEBS J., (2011), 278, 1137-1144.
3. Takeshi Hiromoto, Shinsuke Fujiwara, Keiichi Hosokawa, Hiroshi Yamaguchi, Crystal Structure of 3-Hydroxybenzoate Hydroxylase from Comamonas testosteroni Has a Large Tunnel for Substrate and Oxygen Access to the Active Site. J. Mol. Biol. (2006), 364, 878-896.