The reactions of human beta-amyloid peptide 1-28 (A beta 28) with Al-III and Fe-III ions were investigated by H-1 NMR and electrospray ionization mass spectrometry (ESI-MS) under pH conditions close to physiological ones. H-1 NMR titrations, performed in the 5.3-8.0 pH range, revealed that no measurable amounts of A beta 28-Al-III or A beta 28-Fe-III adducts are formed; such metal adducts could not be obtained even by changing a number of experimental conditions, e.g., temperature, buffer, nature of the salt, etc. These observations were later confirmed by ESI-MS. It is thus demonstrated that A beta 28, at physiological pH, is not able to form binary complexes with Al-III and Fe-III ions of sufficient stability to compete with metal hydroxide precipitation. The biological implications of these findings are discussed in the frame of current literature.
Exploring the reactions of beta-amyloid peptide 1-28 with Al(III) and Fe(III) ions
La Penna G;
2011
Abstract
The reactions of human beta-amyloid peptide 1-28 (A beta 28) with Al-III and Fe-III ions were investigated by H-1 NMR and electrospray ionization mass spectrometry (ESI-MS) under pH conditions close to physiological ones. H-1 NMR titrations, performed in the 5.3-8.0 pH range, revealed that no measurable amounts of A beta 28-Al-III or A beta 28-Fe-III adducts are formed; such metal adducts could not be obtained even by changing a number of experimental conditions, e.g., temperature, buffer, nature of the salt, etc. These observations were later confirmed by ESI-MS. It is thus demonstrated that A beta 28, at physiological pH, is not able to form binary complexes with Al-III and Fe-III ions of sufficient stability to compete with metal hydroxide precipitation. The biological implications of these findings are discussed in the frame of current literature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
