Intermolecular alignment in β2-microglobulin amyloid fibrils

J Am Chem Soc. 2010 Dec 8;132(48):17077-9. doi: 10.1021/ja107987f. Epub 2010 Nov 15.

Abstract

The deposition of amyloid-like fibrils, composed primarily of the 99-residue protein β2-microglobulin (β2m), is one of the characteristic symptoms of dialysis-related amyloidosis. Fibrils formed in vitro at low pH and low salt concentration share many properties with the disease related fibrils and have been extensively studied by a number of biochemical and biophysical methods. These fibrils contain a significant β-sheet core and have a complex cryoEM electron density profile. Here, we investigate the intrasheet arrangement of the fibrils by means of (15)N-(13)C MAS NMR correlation spectroscopy. We utilize a fibril sample grown from a 50:50 mixture of (15)N,(12)C- and (14)N,(13)C-labeled β2m monomers, the latter prepared using 2-(13)C glycerol as the carbon source. Together with the use of ZF-TEDOR mixing, this sample allowed us to observe intermolecular (15)N-(13)C backbone-to-backbone contacts with excellent resolution and good sensitivity. The results are consistent with a parallel, in-register arrangement of the protein subunits in the fibrils and suggest that a significant structural reorganization occurs from the native to the fibril state.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid / chemistry*
  • Models, Molecular
  • Nuclear Magnetic Resonance, Biomolecular
  • Protein Multimerization*
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • beta 2-Microglobulin / chemistry*

Substances

  • Amyloid
  • beta 2-Microglobulin