Higher magnetic field NMR renders resolution enhancement on ganglioside GD3 catalyzed heterogeneous Aβ₄₂ aggregates

Magic-angle spinning (MAS) solid-state NMR (SSNMR) has been widely used to determine amyloid fibril structures at atomic resolution. Such studies typically rely on homogeneous fibril preparations that produce narrow linewidths and high spectral resolution, enabling reliable resonance assignment and structural analysis. However, many biologically relevant amyloid aggregates are structurally heterogeneous, resulting in spectral broadening and reduced sensitivity that hinder atomic-resolution characterization. Lipids are known to modulate amyloid aggregation pathways and promote the formation of toxic species that are often less homogeneous, further complicating NMR-based investigations. Here, we evaluate the feasibility of utilizing the benefits associated with high-field (1.1 GHz) SSNMR for studying ganglioside GD3-catalyzed Aβ₄₂ aggregates. Uniformly-¹³C,¹⁵N-labeled Aβ₄₂ was incubated with GD3 to generate lipid-associated aggregates and analyzed under MAS conditions. ¹³C cross-polarization magic-angle spinning (CPMAS) spectra and 2D¹³C-¹³C chemical shift correlation experiments using CORD (COmbined R2_n^v-Driven) mixing were acquired and compared with data collected at 600 MHz. Despite the heterogeneous nature of the GM1-associated assemblies, the 1.1 GHz spectra exhibit enhanced sensitivity and improved spectral resolution. Better resolved resonances corresponding to selectively structured regions of Aβ₄₂ are observed, indicating the presence of an ordered core within the lipid-associated aggregates. These results demonstrate that ultrahigh-field SSNMR can be advantageous in the characterization of heterogeneous amyloid assemblies and provides a promising approach for atomic-level investigation of biologically relevant, lipid-modulated Aβ aggregates.