For better understanding the molecular basis of the mechanism underlying oligosaccharides functions, it is quite desirable to gain detail information on their conformational dynamics in solution. However, the conformational analysis of oligosaccharides is still a remaining challenge, because of their branched covalent structures and dynamic conformational multiplicities, which hinder conventional analytical methods. For conformational characterization of flexible oligosaccharides, their structures should not be dealt with as a single well-defined global free energy minimum but as an ensemble of low energy conformers. Hence, we have been developing a methodology for evaluating a dynamic ensemble of oligosaccharide conformations by employing paramagnetic-assisted NMR methods based on paramagnetic effects such as pseudocontact shift (PCS) and paramagnetic relaxation enhancement (PRE) in conjunction with molecular dynamics (MD) simulations [1,2]. We applied this approach to the conformational dynamics analyses of branched GM2 tetrasaccharide, βGalNAc-(1-4)-[αNeu5Ac-(2-3)]-βGal-(1-4)-βGlc, which share the common core structure of gangliosides forming an integral part of cellular membranes. We synthesized the GM2 tetrasaccharide covalently attached to a lanthanide chelating-tag (Fig. 1). Upon complexation with paramagnetic lanthanide ions, the tagged sugar exhibited NMR spectral changes due to PCSs. The observed PCS values were in excellent agreement with those back-calculated from the 3D ensemble models derived from the MD calculations. In addition, we have developed spin-labeling method of gangliosides for their NMR analyses in amphipathic environments. These methodologies open a new prospect for conformational analyses of dynamic structures of gangliosides toward decoding glycocodes from the 3D structural aspects.
저자
Ying Zhang [ Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences and Department of Functional Molecular Science, The Graduate University for Advanced Studies (SOKENDAI), 5-1 Higashiyama, , Myodaiji, Okazaki, 444-8787, Japan, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan ]
Takumi Yamaguchi [ Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences and Department of Functional Molecular Science, The Graduate University for Advanced Studies (SOKENDAI), 5-1 Higashiyama, , Myodaiji, Okazaki, 444-8787, Japan, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan ]
Sayoko Yamamoto [ Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences and Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan ]
Yoshinori Uekusa [ Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences and Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan ]
Koichi Kato [ Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences and Department of Functional Molecular Science, The Graduate University for Advanced Studies (SOKENDAI), 5-1 Higashiyama, , Myodaiji, Okazaki, 444-8787, Japan, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan ]
본 학회는 화학, 생화학, 분자생물학, 미생물학, 식품공학, 의학, 약학, 유전공학 및 생물공학, 환경 및 기타 공업 등 전 분야의 탄수화물관련 이론과 기술을 연구 발전시키고 산학협동을 통해 이를 보급하여 국내 관련 산업의 발전 및 국민생활의 과학화에 기여하고자 하며, 이러한 목표와 비젼의 실현을 위해 회원들이 적극적인 참여와 활동을 전개하고자 한다.