College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
National Engineering Research Center for Fruit & Vegetable Processing, Beijing 100083, China.
Molecules. 2022 Dec 7;27(24):8661. doi: 10.3390/molecules27248661.
(1) Background: (-)-Epigallocatechin-3-gallate (EGCG) has been reported to improve mitochondrial function in cell models, while the underlying mechanism is not clear. Cyclophilin D (CypD) is a key protein that regulates mitochondrial permeability transition pore (mPTP) opening. (2) Methods: In this study, we found that EGCG directly binds to CypD and this interaction was investigated by surface plasmon resonance (SPR), nuclear magnetic resonance (NMR) and molecular dynamic (MD) simulation. (3) Results: SPR showed an affinity of 2.7 × 10 M. The binding sites of EGCG on CypD were mapped to three regions by 2D NMR titration, which are Region 1 (E23-V29), Region 2 (T89-G104) and Region 3 (G124-I133). Molecular docking showed binding interface consistent with 2D NMR titration. MD simulations revealed that at least two conformations of EGCG-CypD complex exist, one with E23, D27, L90 and V93 as the most contributed residues and E23, L5 and I133 for the other. The major driven force for EGCG-CypD binding are Van der Waals and electrostatic interactions. (4) Conclusions: These results provide the structural basis for EGCG-CypD interaction, which might be a potential mechanism of how EGCG protects mitochondrial functions.
（1）背景：（-）-表没食子儿茶素没食子酸酯（EGCG）已被报道可改善细胞模型中的线粒体功能，但其潜在机制尚不清楚。亲环素 D（CypD）是调节线粒体通透性转换孔（mPTP）开放的关键蛋白。（2）方法：在本研究中，我们发现 EGCG 可直接与 CypD 结合，通过表面等离子体共振（SPR）、核磁共振（NMR）和分子动力学（MD）模拟研究了这种相互作用。（3）结果：SPR 显示出 2.7×10-5 M 的亲和力。通过 2D NMR 滴定，将 EGCG 在 CypD 上的结合位点映射到三个区域，分别为区域 1（E23-V29）、区域 2（T89-G104）和区域 3（G124-I133）。分子对接显示结合界面与 2D NMR 滴定一致。MD 模拟表明 EGCG-CypD 复合物至少存在两种构象，一种构象以 E23、D27、L90 和 V93 为最主要贡献残基，另一种构象以 E23、L5 和 I133 为最主要贡献残基。EGCG-CypD 结合的主要驱动力是范德华力和静电相互作用。（4）结论：这些结果为 EGCG-CypD 相互作用提供了结构基础，这可能是 EGCG 保护线粒体功能的潜在机制。
