Poster Presentation 23rd International Society of Magnetic Resonance Conference 2023

Expeditious Characterization of Aβ Fibrils by 1H-detected SSNMR (#222)

Ayesha Wickramasinghe 1 , Yiling Xiao 2 , Maho Yagi-Utsumi 3 4 , Saeko Yanaka 3 4 , Koichi Kato 3 4 , Yoshitaka Ishii 1 2 5
  1. RIKEN Center for Biosystems Dynamics Research, RIKEN, Yokohama, Kanagawa, Japan
  2. Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois, USA
  3. Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi, Japan
  4. Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, Japan
  5. School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Kanagawa, Japan

Fibrillar assemblies of amyloid-beta (Aβ) fibrils have been a subject of intense scrutiny due to their close association with Alzheimer’s disease (AD). Structural characterization of Aβ fibrils is crucial for a profound understanding of the mechanism of AD. However, due to their insoluble and non-crystalline nature, it has been difficult to characterize Aβ fibrils by conventional structural tools such as solution NMR and X-ray crystallography. SSNMR spectroscopy has been the most powerful analytical technique to determine the atomic level structures of Aβ fibrils. Thus, conventional 13C-detected SSNMR is a common practice in Aβ research.1-2 However, the requirement of a large amount of sample (several mg) to record the NMR spectra with sufficient sensitivity is a bottleneck of this technique. Furthermore, high-dimensional NMR spectra (typically above 3D) are required to achieve sufficient resolution for a reliable resonance assignment, which subsequently demands prolonged experiment time. However, these requirements, which are often nonviable in 13C-detected SSNMR, limit practical biological applications. With recent advances, 1H-detected high-dimensional SSNMR can circumvent the above limitations of traditional SSNMR.3-4 Thus, in this study, we present our recent progress in the expeditious structural characterization of synthetic and brain-derived Aβ42 fibrils in nano-mole scale (~40 nmol) by 1H-detected high-dimensional SSNMR under UFMAS integrated with non-uniform sampling (NUS) protocols. Furthermore, we discuss the effect of gravity on the fibril structure by a comparative analysis of 1H-detected 3D SSNMR spectral data of an Aβ40 fibril prepared at the International Space Station (ISS) with its Control sample fibrillized on earth.5

  1. Xiao et al., Nat. Struct. Mol. Biol. 2015, 22, 499-505. 2. Ghosh et al., Proc. Natl. Acad. Sci. USA 2021, 118, e2023089118. 3. Ishii et al., J. Magn. Reson. 2018, 286, 99-109. 4. Wickramasinghe et al., J. Am. Chem. Soc. 2021, 143, 11462-11472. 5. Yagi-Utsumi et al., npj Microgravity 2020, 6, 17.