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Direct observation of minimum‐sized amyloid fibrils using solution NMR spectroscopy
Author(s) -
Yoshimura Yuichi,
Sakurai Kazumasa,
Lee YoungHo,
Ikegami Takahisa,
Chatani Eri,
Naiki Hironobu,
Goto Yuji
Publication year - 2010
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1002/pro.515
Subject(s) - fibril , chemistry , nuclear magnetic resonance spectroscopy , heteronuclear molecule , two dimensional nuclear magnetic resonance spectroscopy , amyloid fibril , monomer , heteronuclear single quantum coherence spectroscopy , molecule , spectroscopy , crystallography , polymer , amyloid β , stereochemistry , organic chemistry , biochemistry , medicine , physics , disease , pathology , quantum mechanics
It is challenging to investigate the structure and dynamics of amyloid fibrils at the residue and atomic resolution because of their high molecular weight and heterogeneous properties. Here, we used solution nuclear magnetic resonance (NMR) spectroscopy to characterize the conformation and flexibility of amyloid fibrils of β 2 ‐microglobulin (β2m), 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 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 β2m 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.