Amyloid beta-peptide spin trapping. II: Evidence for decomposition of the PBN spin adduct.
Synthetic beta-amyloid peptides (A betas) react with the spin trap phenyl-tert-butyl nitrone (PBN) to form products detectable by electron paramagnetic resonance (EPR) spectroscopy. At least two EPR-detectable products can be distinguished from the A beta/PBN reaction, and peptide toxicity towards glutamine synthetase enzyme correlates with the type of PBN reaction product observed. We have reacted synthetic A beta(25-35) peptide with [12C]- or [13C]PBN to demonstrate that the two products represent alternate pathways of spin adduct decomposition. Results indicate that the C=N bond of PBN is cleaved by A beta in what we hypothesize is a radical addition-fragmentation reaction.
Hensley
K
K
Department of Chemistry, University of Kentucky, Lexington 40506, USA.
Aksenova
M
M
Carney
J M
JM
Harris
M
M
Butterfield
D A
DA
D016229:Amyloid beta-Peptides / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D010455:Peptides / Q000737:chemistry*
D016229:Amyloid beta-Peptides; D005609:Free Radicals; D010455:Peptides