Intermolecular Alignment in Beta 2-Microglobulin Amyloid Fibrils

• Main Authors: Debelouchina, Galia Tzvetanova (Contributor), Bayro, Marvin J. (Contributor), Radford, Sheena E. (Author), Griffin, Robert Guy (Contributor), Platt, Geoffrey W. (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Chemistry (Contributor), Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology) (Contributor)
• Format: Article
• Language: English
• Published: American Chemical Society (ACS), 2012-08-07T18:27:38Z.
• Subjects: Article
• Online Access: Get fulltext

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 [superscript 15]N−[superscript 13]C MAS NMR correlation spectroscopy. We utilize a fibril sample grown from a 50:50 mixture of [superscript 15]N,[superscript 12]C- and [superscript 14]N,[superscript 13]C-labeled β2m monomers, the latter prepared using 2-[superscript 13]C glycerol as the carbon source. Together with the use of ZF-TEDOR mixing, this sample allowed us to observe intermolecular [superscript 15]N−[superscript 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.
National Institutes of Health (U.S.) (grant no. EB003151)
National Institutes of Health (U.S.) (grant no. EB002026)
National Institutes of Health (U.S.) (grant no. P41 RR-01081)
Wellcome Trust (London, England) (grant no. 075675)
Wellcome Trust (London, England) (grant no. 062164)