Zn(II) ions substantially perturb Cu(II) ion coordination in amyloid-β at physiological pH.

ABSTRACT: The interaction of Cu(II) and Zn(II) ions with amyloid-β (Aβ) plays an important role in the etiology of Alzheimer's disease. We describe the use of electron spin resonance (ESR) to measure metal-binding competition between Cu(II) and Zn(II) in amyloid-β at physiological pH. Continuous wave ESR measurements show that the affinity of Cu(II) toward Aβ(1-16) is significantly higher than that of Zn(II) at physiological pH. Importantly, of the two known Cu(II) coordination modes in Aβ, component I and component II, Zn(II) displaces Cu(II) only from component I. Our results indicate that at excess amounts of Zn(II) component II becomes the most dominant coordination mode. This observation is important as Aβ aggregates in the brain contain a high Zn(II) ion concentration. In order to determine de

SUBMITTER: Silva KI 

PROVIDER: S-EPMC3775258 | biostudies-literature | 2013 Aug

REPOSITORIES: biostudies-literature