ß-Amyloid peptide solubility

[Joaquin Arribas]

Hi, I need some help

In my experiments I add different ß-Amyloid peptides (10-20; 1-28; 
1-40) at concentrations 100µM to the media (plain DME) of cells in 
culture. Usually I don't have any problems and the peptides remain 
in solution in DME. However, when I do the same experiments using 
cells that have been metabolically labeled with 35S-Meth the peptide 
ß-Amyloid 1-40 precipitates even when the metabolically labeled 
cells have been extensively washed with DME. Do you know what may be 
affecting the solubility of ß-Amyloid 1-40?. I do not have any 
problems with ß-Amyloid 10-20 o 1-28 under the same conditions. Any 
suggestions?

THANKS