Direct observation of minimum-sized amyloid fibrils using solution NMR spectroscopy.

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Direct observation of minimum-sized amyloid fibrils using solution NMR spectroscopy.

Related Articles Direct observation of minimum-sized amyloid fibrils using solution NMR spectroscopy.

Protein Sci. 2010 Oct 8;

Authors: Yoshimura Y, Sakurai K, Lee YH, Ikegami T, Chatani E, Naiki H, Goto Y

It is challenging to investigate the structure and dynamics of amyloid fibrils at the residue and atomic resolution due to their high molecular weight and heterogeneous properties. Here, we employed solution nuclear magnetic resonance (NMR) spectroscopy to characterize the conformation and flexibility of amyloid fibrils of ?(2)-microglobulin (?2m), for which direct observation of solution NMR could not be made. Ultrasonication led to fragmentation producing a solution of minimum-sized fibrils with a molecular weight of around 6 MDa. In (1)H-(15)N heteronuclear single-quantum correlation (HSQC) measurements, five signals, derived from N-terminal residues (i.e. Ile1, Gln2, Arg3, Thr4 and Lys6), were newly detected. Signal strength decreased with the distance from the N-terminal end. Capping experiments with the unlabeled ?2m monomer indicated that the signals originated from molecules located inside the fibrils. Ultrasonication makes the residues with moderate flexibility observable by reducing size of the fibrils. Thus, solution NMR measurements of ultrasonicated fibrils will be promising for studying the structure and dynamics of fibrils.

PMID: 20936689 [PubMed - as supplied by publisher]



Source: PubMed