Istituto di Biostrutture e Bioimmagini (IBB)-CNR and CIRPeB; Via Mezzocannone 16, Napoli 80134, Italy.
Molecular Modeling Section, Dipartimento di Scienze del Farmaco, Università di Padova, via F. Marzolo 5, 35131 Padova, Italy.
Biochem J. 2018 Jul 31;475(14):2377-2393. doi: 10.1042/BCJ20180177.
The complex formation between the proteins apoptosis-inducing factor (AIF) and cyclophilin A (CypA) following oxidative stress in neuronal cells has been suggested as a main target for reverting ischemia-stroke damage. Recently, a peptide encompassing AIF residues 370-394 has been developed to target the AIF-binding site on CypA, to prevent the association between the two proteins and suppress glutamate-induced cell death in neuronal cells. Using a combined approach based on NMR spectroscopy, synthesis and testing of all Ala-scan mutants of the peptide and molecular docking/molecular dynamics, we have generated a detailed model of the AIF (370-394)/CypA complex. The model suggests us that the central region of the peptide spanning residues V374-K384 mostly interacts with the protein and that for efficient complex inhibition and preservation of CypA activity, it is bent around amino acids F46-G75 of the protein. The model is consistent with experimental data also from previous works and supports the concept that the peptide does not interfere with other CypA activities unrelated to AIF activation; therefore, it may serve as an ideal template for generating future non-peptidic antagonists.
氧化应激诱导神经元细胞中凋亡诱导因子（AIF）与亲环蛋白 A（CypA）形成复合物，这被认为是逆转缺血性中风损伤的主要靶点。最近，开发了一种包含 AIF 残基 370-394 的肽，以靶向 CypA 上的 AIF 结合位点，防止两种蛋白质的结合，并抑制谷氨酸诱导的神经元细胞死亡。我们使用基于 NMR 光谱学、合成和测试肽的所有 Ala 扫描突变体以及分子对接/分子动力学的综合方法，生成了 AIF（370-394）/CypA 复合物的详细模型。该模型表明，肽的中心区域（残基 V374-K384）主要与蛋白质相互作用，为了有效地抑制复合物并保留 CypA 活性，该区域围绕蛋白质的氨基酸 F46-G75 弯曲。该模型与之前的实验数据也一致，并支持这样的概念，即该肽不会干扰与 AIF 激活无关的其他 CypA 活性；因此，它可以作为生成未来非肽类拮抗剂的理想模板。
