Biological Oxidations and Nitrations Promoted by the Hemin–Aβ16 Complex

Both β-amyloid (Aβ) peptides and oxidative stress conditions play key roles in Alzheimer’s disease. Hemin contributes to the development of disease as it possesses redox properties its level increases pathological or traumatic brain injuries. The aim this work was deepen investigation reactivity hemin–Aβ16 complex, considering ability catalyze oxidation nitration reactions. We performed kinetic studies presence hydrogen peroxide nitrite with phenolic catechol substrates, well mass spectrometry investigate modifications occurring on peptide itself. constants were similar for reactions, their values suggest that complex binds negatively charged substrates higher affinity. Mass showed tyrosine residue is endogenous target nitration. degradation analysis hemin bleaching only partly prevented by coordinated peptide. In conclusion, has rich reactivity, both reactions aromatic could contribute equilibrium neurons. This modulated coordination Aβ16 quenched when nitrative lead degradation.