Solid-State NMR Studies Reveal Native-like β-Sheet Structures in Transthyretin Amyloid

Area of Science:

• Biochemistry
• Structural Biology
• Biophysics

Background:

• Amyloid formation, characterized by cross-β structures, is linked to various human diseases.
• Determining the β-sheet structure in noncrystalline amyloid presents significant challenges.

Purpose of the Study:

• To structurally characterize the β-sheet structure in full-length transthyretin (TTR) amyloid.
• To investigate the stability of native β-sheet structures within the amyloid state.

Main Methods:

• Utilized magic-angle-spinning (MAS) solid-state NMR spectroscopy.
• Employed selective labeling schemes (e.g., (13)CO- and (13)Cα-labeled TTR) for enhanced NMR studies.
• Analyzed long-range (13)C-(13)C correlation MAS spectra.

Main Results:

• Confirmed the persistence of the native CBEF and DAGH β-sheets in TTR amyloid.
• Demonstrated the utility of MAS solid-state NMR for studying amyloid structures.
• Obtained tertiary structural information relevant to TTR amyloid quaternary structure.

Conclusions:

• The core β-sheet structures of transthyretin are preserved in the amyloid state.
• Solid-state NMR is a powerful technique for elucidating amyloid structures.
• Findings contribute to understanding the molecular basis of amyloid-related diseases.