Mancl Jordan M, Wu Xiaoyang, Zhao Minglei, Tang Wei-Jen
Ben-May Department for Cancer Research, University of Chicago, Chicago,Illinois, United States.
Department of Biochemistry and Molecular Biology,University of Chicago, Chicago, Illinois, United States.
Elife. 2025 Sep 24;14:RP106044. doi: 10.7554/eLife.106044.
Angiotensin-I converting enzyme (ACE) regulates the levels of disparate bioactive peptides, notably converting angiotensin-I to angiotensin-II and degrading amyloid beta. ACE is a heavily glycosylated dimer, containing four analogous catalytic sites, and exists in membrane-bound and soluble (sACE) forms. ACE inhibition is a frontline, FDA-approved, therapy for cardiovascular diseases yet is associated with significant side effects, including higher rates of lung cancer. To date, structural studies have been confined to individual domains or partially denatured cryo-EM structures. Here, we report the cryo-EM structure of the glycosylated full human sACE dimer. We resolved four structural states at 2.99 - 3.65 Å resolution which are primarily differentiated by varying degrees of solvent accessibility to the active sites and reveal the full dimerization interface. We also employed all-atom molecular dynamics (MD) simulations and heterogeneity analysis in cryoSPARC, cryoDRGN, and RECOVAR to elucidate the conformational dynamics of sACE and identify key regions mediating conformational change. We identify differences in the mechanisms governing the conformational dynamics of individual domains that have implications for the design of domain-specific sACE modulators.
血管紧张素转换酶（ACE）调节多种生物活性肽的水平，特别是将血管紧张素I转化为血管紧张素II并降解β淀粉样蛋白。ACE是一种高度糖基化的二聚体，包含四个类似的催化位点，以膜结合形式和可溶性（sACE）形式存在。ACE抑制是一种经美国食品药品监督管理局（FDA）批准的心血管疾病一线治疗方法，但会产生显著的副作用，包括肺癌发病率升高。迄今为止，结构研究仅限于单个结构域或部分变性的冷冻电镜结构。在此，我们报道了糖基化的完整人sACE二聚体的冷冻电镜结构。我们以2.99 - 3.65 Å的分辨率解析了四种结构状态，这些状态主要通过活性位点不同程度的溶剂可及性来区分，并揭示了完整的二聚化界面。我们还在cryoSPARC、cryoDRGN和RECOVAR中采用全原子分子动力学（MD）模拟和异质性分析，以阐明sACE的构象动力学，并确定介导构象变化的关键区域。我们确定了控制各个结构域构象动力学的机制差异，这对结构域特异性sACE调节剂的设计具有启示意义。
