Invited Speaker 23rd International Society of Magnetic Resonance Conference 2023

Sensitivity-Enhanced Protein Solid-state NMR using Ultra-fast MAS and its Applications to Amyloid Proteins: Innovations and Dilemma (#96)

Yoshitaka Ishii 1 2
  1. Tokyo Institute of Technology, Yokohama, KANAGAWA, Japan
  2. BDR Center, RIKEN, Yokohama, Japan

We discuss recent progress and relevant innovations in biological solid-state NMR (SSNMR) using fast magic angle spinning (MAS) and its applications to amyloid and other proteins in our laboratories. First, we present our progress in the structural examination of misfolded amyloid-β (Ab) by SSNMR. Increasing evidence suggests that misfolded aggregates of 42-residue Aβ42, rather than more abundant Aβ40, provokes the Alzheimer’s cascade. Our SSNMR study recently revealed a unique S-shaped structure of Aβ42 amyloid fibril for the first time.1 Here, we discuss our ongoing efforts to examine the feasibility of characterizing the structure of trace amounts of brain-derived and synthetic amyloid fibrils by sensitivity-enhanced 1H-detected SSNMR under ultra-fast MAS (UFMAS) and by 1H-detected 3D and 4D SSNMR.2 CryoEM and SSNMR analysis of Ab fibril associated with familial Alzheimer’s will be also presented.

Second, we present our progress in resolution/sensitivity enhancement in 1H-detected biomolecular SSNMR under UFMAS conditions (≥ 80 kHz) in a high magnetic field (750-900 MHz).2,3 Our data on protein microcrystal GB1 and Aβ fibril show that traditionally time-consuming 3-5D biomolecular SSNMR is feasible for signal assignments in a nano-mole-scale. We also present a series of novel schemes for polarization transfer to further speed up the high-dimensional SSNMR experiments. The ongoing development of a MAS probe that allows for spinning at 160 kHz is also discussed. Some preliminary SSNMR data will be presented with prospects and challenges in spinning at a faster rate.

Lastly, we discuss our progress toward the development of a 1.3 GHz NMR system supported by the Japan Science Technology Agency. The recent milestones from the project include the development of an ultra-compact 1.01-GHz NMR magnet and its NMR applications.  We introduce the new ultra-compact 1.01-GHz NMR system, which utilizes high-temperature superconducting coils besides conventional low-temperature superconducting coils. Some preliminary NMR data from the 1.01-GHz NMR system will be presented with future development prospects.

References:

[1] Xiao, Y.et al. Nat. Struct. Mol. Biol. 2015, 22, 499.

[2] Wickramasinghe, N.et al. Nat. Methods 2009, 6, 215.

[3] Ishii, Y.et al. J. Magn. Reson. 2018, 286, 99.

[4] Matsunaga, T. et. al. J. Magn. Reson. 2021, 322, 106857.