Figure 4
From: High-resolution NMR characterization of low abundance oligomers of amyloid-β without purification
The disordered Aβ1-40 oligomer grows in size while maintaining its morphology.
(a) DLS experiments at 19 days demonstrate that the disordered oligomer not only remains disordered, but also grows in size as well with a distribution of hydrodynamic radii at 8.6 nm and 65.3 nm and polydispersity of 14.9% and 37.8%, respectively. (b) The strong minimum at ~200 nm in the CD spectrum of the disordered oligomer after 19 days reveals that the oligomer does not progress to a fibrillar state. Two-dimensional spectra of the fingerprint region of (c) TOCSY (70 ms mixing) and (d) NOESY (250 ms mixing) of the disordered Aβ1–40 oligomers recorded at 4 days (blue) and 19 days (red). The filtered oligomer sample was lyophilized and re-hydrated to double its initial concentration, making for a total Aβ1-40 of ~35 μM. After 19 days (red), almost all peaks are broadened beyond detection in both TOCSY and NOESY spectra.
