Binding of heme to the amyloid peptides Aβ40/42 is thought to be an initial step in the development of symptoms in the early stages of Alzheimers disease by enhancing the intrinsic peroxidatic activity of heme. We found considerably higher acceleration of the reaction for the physiologically relevant neurotransmitters dopamine and serotonin than reported earlier for the artificial substrate 3,3',5,5'-tetramethylbenzidine (TMB). Thus, the binding of hemin to Aβ peptides might play an even more crucial role in the early stages of Alzheimers disease than deduced from these earlier results. To mimic complex formation, a new surface architecture has been developed: The interaction between the truncated amyloid peptide Aβ1-16 and hemin immobilized on an aminohexanethiol spacer on a gold electrode has been analyzed by cyclic voltammetry. The resulting complex has a redox pair with a 25 mV more cathodic formal potential than hemin alone.
Neumann, Bettina, Aysu Yarman, Ulla Wollenberger, Frieder Scheller
Anal Bioanal Chem