Actually, abeta fibril formation is greatly influenced by DMSO. At 100% DMSO the peptide is a monomer. Diluting the DMSO down to around 10% will induce fibril formation,

http://www.jbc.org/content/272/34/21037.full

http://www.pnas.org/content/102/48/17342.full

Article Specific Binding of Alzheimer’s Abeta Peptide Fibrils to Sin...

Even low concentrations of DMSO (5-10%) will slow aggregation slightly, although this may depend on the specific preparation procedure.

http://peds.oxfordjournals.org/content/early/2011/05/11/protein.gzr020.full

The conformation of Abeta1-40 in 10% and 0% DMSO is probably similar, since they give nearly identical NMR spectra (unpublished results)

Well DMSO can be used to have a dual effect.

I have used 70% DMSO to depolymerise preformed Abeta amyloid fibrils (ThT fluorescence).

And to opposite of the above effect.... I have used 5-10% DMSO to induce Abeta amyloid fibril formation (included vigorous agitation at 45 deg C).

Although it does not answer your question ... but I am sure you can use dilute conc of DMSO to prevent Abeta aggregation.

One thing which u can do is - make Abeta amyloid fibrils, then take a portion of it and incubate in different conc of DMSO for 10 mins (in a 20ul rxn volume). Measure Tht fluorescence. This would tell you the lowest DMSO conc required for keeping the abeta monomeric. Hope this helps.