Measurements of 13C multiple-quantum coherences in amyloid fibrils under magic-angle spinning.
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.
Department of Chemistry, National Taiwan University, No. 1, Section 4, Roosevelt Road, Taipei, Taiwan.
Fang-Chieh
FC
Chou
Tim W T
TW
Tsai
Hsin-Mei
HM
Cheng
Jerry C C
JC
Chan
D000409:Alanine / Q000737:chemistry; D000682:Amyloid / Q000737:chemistry*; D002247:Carbon Isotopes / Q000737:chemistry; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular; D011328:Prions / Q000737:chemistry; D017433:Protein Structure, Secondary; D011789:Quantum Theory
D000682:Amyloid; D002247:Carbon Isotopes; D011328:Prions; D000409:Alanine