Development of next geranaration solid-state NMR methods and applications to amyloid-ligand interactions

2021 Fiscal Year Final Research Report

• Project/Area Number: 15K21772
• Research Category: Fund for the Promotion of Joint International Research (Home-Returning Researcher Development Research)
• Allocation Type: Multi-year Fund
• Research Field: Structural biochemistry
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Ishii Yoshitaka 東京工業大学, 生命理工学院, 教授 (40799045)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Keywords: 固体NMR / 構造生物学

Outline of Final Research Achievements

In this study, we developed the next-generation methodologies of solid-state NMR (SSNMR) and applied SSNMR to amyloid structural biology in the following three projects. In order to enhance sensitivity and resolution, the lack of which has been fundamental problems for NMR-based structural biology, we developed (1) SSNMR methods for observing trace biological samples using ultrafast magic-angle-spinning (MAS) method and (2) high-dimensional SSNMR for improving resolution. (3) We aimed to advance structural biology on the interactions between ligand molecules and amyloid proteins related to Alzheimer's disease. It was suggested that the structure of 42-residue amyloid beta fibrils bound to tea-derived catechin EGCG did not change significantly except for the side chains that could be the binding sites. Through this study, significant progress has been made in SSNMR of biological samples.

Free Research Field

固体NMR、構造生物学、アルツハイマー病

Academic Significance and Societal Importance of the Research Achievements

課題(1)では、超高速MAS法を使った感度増加法を開発し、従来法では検出限界以下である数nmolの試料での測定を可能とすることを示せた。課題(2)では、構造の不均一性のため従来法では信号帰属が困難であった繊維状Aβ42アミロイドに対して、４次元固体NMRが2日程度で測定できることも示せた。この手法から得られる高分解能により、３次元固体NMRデータと併せてこの試料の信号の完全帰属と２次構造解析が可能となった。また課題(３)では、微量の抗体とタンパク質GB1の複合体試料から抗体の結合によりGB1の構造が大きく変化することを示した。抗体医薬等への応用も将来的に可能な技術と考えられる。