Measurements of C-13 Multiple-Quantum Coherences in Amyloid Fibrils under Magic-Angle Spinning
Journal
Journal of Physical Chemistry B
Journal Volume
116
Journal Issue
24
Pages
7162-7167
Date Issued
2012
Author(s)
Abstract
The excitation and detection of high-order multiple quantum coherences among (13)C nuclear spins are demonstrated in the samples of [1-(13)C]-L-alanine and (13)C labeled amyloid fibrils at a spinning frequency of 20 kHz. The technique is based on the double-quantum average Hamiltonian prepared by the DRAMA-XY4 pulse sequence. Empirically, we find that multiple supercycles are required to suppress the higher-order effects for real applications. Measurements for the fibril samples formed by the polypeptides of PrP(113-127) provide the first solid-state NMR evidence for the stacking of multiple β-sheet layers at the structural core of amyloid fibrils.
Type
journal article