Żukowska Joanna, Gregory Kyle S, Robinson Adam, Isaac R Elwyn, Acharya K Ravi
Department of Life Sciences, University of Bath, Claverton Down, Bath BA2 7AY, UK.
Institute of Integrative and Comparative Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
Biomolecules. 2025 Apr 16;15(4):591. doi: 10.3390/biom15040591.
Human angiotensin-I-converting enzyme (ACE) is involved in vasoregulation, inflammation, and neurodegenerative disorders. The enzyme is formed of two domains; the C-domain (cACE) is primarily involved in blood pressure regulation, whereas the N-domain (nACE) is strongly linked to fibrosis; hence, designing domain-specific inhibitors could make a difference between treating one condition without having a negative effect on another. AnCE (a close homologue of ACE) is derived from and has a high similarity specifically to cACE. Due to high similarity and ease of crystallisation, AnCE has been chosen as a model protein for ACE studies and for the design of ACE inhibitors. In this study, enzyme kinetic assays and X-ray crystallography techniques revealed the significance of using dipeptides as selective inhibitors for AnCE and how this knowledge could be applied to cACE and nACE. All the dipeptides tested in this study were shown to bind AnCE in two distinct locations, i.e., the non-prime and prime subsites. It was found that a hydrophobic residue at the S1 and S1' subsites, with a tryptophan at the S2 and S2' subsites, showed highest affinity towards AnCE. It was also observed that a key pocket within the S2' subsite had a major influence on the binding orientation within the prime subsites and could potentially explain ACE's dipeptidyl carboxypeptidase activity. Importantly these dipeptides are found in functional foods, making them potentially available from diets. Knowledge of the dipeptide binding presented here could aid in the development of ACE domain-specific inhibitors.
人血管紧张素转换酶（ACE）参与血管调节、炎症和神经退行性疾病。该酶由两个结构域组成；C结构域（cACE）主要参与血压调节，而N结构域（nACE）与纤维化密切相关；因此，设计结构域特异性抑制剂可能会在治疗一种疾病时不对另一种疾病产生负面影响方面发挥作用。AnCE（ACE的紧密同源物）源自并与cACE具有高度相似性。由于高度相似且易于结晶，AnCE已被选为ACE研究和ACE抑制剂设计的模型蛋白。在这项研究中，酶动力学测定和X射线晶体学技术揭示了使用二肽作为AnCE选择性抑制剂的重要性以及如何将这一知识应用于cACE和nACE。本研究中测试的所有二肽均显示在两个不同位置结合AnCE，即非prime和prime亚位点。发现S1和S1'亚位点的疏水残基以及S2和S2'亚位点的色氨酸对AnCE具有最高亲和力。还观察到S2'亚位点内的一个关键口袋对prime亚位点内的结合方向有重大影响，并可能解释ACE的二肽基羧肽酶活性。重要的是，这些二肽存在于功能性食品中，使它们有可能从饮食中获取。此处介绍的二肽结合知识可能有助于开发ACE结构域特异性抑制剂。
