J Am Chem Soc. 2010 Nov 15. [Epub ahead of print]
Intermolecular Alignment in β(2)-Microglobulin Amyloid Fibrils.
Department of Chemistry and Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States, and Astbury Centre for Structural Molecular Biology and Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, U.K.
Abstract
The deposition of amyloid-like fibrils, composed primarily of the 99-residue protein β(2)-microglobulin (β(2)m), 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 β(2)m 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.PMID: 21077676 [PubMed - as supplied by publisher]
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