Revisit the E2 Domain of Amyloid Precursor Protein: Ferroxidase, Superoxide and Peroxynitrite Scavenging Activities
作者:Andrew T. Poore、Eli C. Zuercher、Gabriel Bury、Caslyn Whitesell、Cuong C. Nguyen、Yulia N. Pushkar、Shiliang Tian
DOI:10.1021/acs.inorgchem.3c01336
日期:2023.7.10
with Alzheimer’s disease (AD). The function of APP is of great interest yet remains elusive. One of the extracellular domains of APP, the E2 domain, has been proposed to possess ferroxidase activity and affect neuronal iron homeostasis. However, contradicting evidence has been reported, and its precise role remains inconclusive. Here, we studied the Cu-binding site of the E2 domain using extended X-ray
淀粉样蛋白前体蛋白 (APP) 是 β-淀粉样蛋白的生物前体,β-淀粉样蛋白是与阿尔茨海默病 (AD) 相关的已知组织病理学标志。APP的功能让人很感兴趣,但仍然难以捉摸。APP 的胞外结构域之一,即 E2 结构域,已被认为具有亚铁氧化酶活性并影响神经元铁稳态。然而,已经报道了相互矛盾的证据,其确切作用仍然没有定论。在这里,我们使用扩展 X 射线吸收精细结构 (EXAFS)、UV-vis 和电子顺磁共振 (EPR) 研究了 E2 结构域的 Cu 结合位点,并发现一种新的不稳定水配体与 Cu(II ) 除了四种已知组氨酸之外的辅因子。2 M –1 s –1。Cu(I)-E2 与分子氧的反应速率仅为 5.3 M –1 s –1,这会将任何潜在的多周转亚铁氧化酶活性限制在如此低的速率,并阻止在多周转条件下观察活性。蛋白质的正静电势表面表明可能与带负电的小底物发生反应,例如超氧自由基 (O 2 •–