Influence of solvent and counter ion on complexes of 2,5-bis(2-pyridyl)-1,3,4-oxadiazole with iron (II) and (III) studied by electrospray ionization mass spectrometry

An electrospray ionization mass spectrometric study of iron binding to amyloid-beta peptides

Iron and other metal ions appear to play an important role in protein aggregation and are therefore likely to provide a link between protein aggregation and oxidative damage. This work reports on iron binding to amyloid- beta peptide (Abeta1-40), which affords a very specific electrospray ionization mass spectrometric (MS) spectrum. Both MS and MS/MS study confirmed that amyloid-beta peptide displays a high affinity toward iron(III) ions, producing multi charged molecular ions and peptide aggregates. Finally, the circular dichroism spectra indicate an unexpected modification of Abeta1-40 peptide conformation upon iron binding.