文摘
The reactions of human 尾-amyloid peptide 1鈥?8 (A尾28) with AlIII and FeIII ions were investigated by 1H NMR and electrospray ionization mass spectrometry (ESI-MS) under pH conditions close to physiological ones. 1H NMR titrations, performed in the 5.3鈥?.0 pH range, revealed that no measurable amounts of A尾28-AlIII or A尾28-FeIII 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尾28, at physiological pH, is not able to form binary complexes with AlIII and FeIII ions of sufficient stability to compete with metal hydroxide precipitation. The biological implications of these findings are discussed in the frame of current literature.
