College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.
Center for Biotechnology and Interdisciplinary Studies, Department of Chemistry and Chemical Biology, Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, USA.
Nat Commun. 2021 Feb 12;12(1):986. doi: 10.1038/s41467-021-21258-5.
Epigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, μM interaction between EGCG and the tumor suppressor p53 (K = 1.6 ± 1.4 μM), with the disordered N-terminal domain (NTD) identified as the major binding site (K = 4 ± 2 μM). Large scale atomistic simulations (>100 μs), SAXS and AUC demonstrate that EGCG-NTD interaction is dynamic and EGCG causes the emergence of a subpopulation of compact bound conformations. The EGCG-p53 interaction disrupts p53 interaction with its regulatory E3 ligase MDM2 and inhibits ubiquitination of p53 by MDM2 in an in vitro ubiquitination assay, likely stabilizing p53 for anti-tumor activity. Our work provides insights into the mechanisms for EGCG's anticancer activity and identifies p53 NTD as a target for cancer drug discovery through dynamic interactions with small molecules.
表没食子儿茶素没食子酸酯（EGCG）源自绿茶，可诱导癌细胞凋亡，但其中的潜在分子机制尚不清楚。本文利用 SPR 和 NMR，首次报道 EGCG 与抑癌蛋白 p53 之间存在直接的、μM 级别的相互作用（Kd=1.6±1.4 μM），且无序的 N 端结构域（NTD）是主要的结合位点（Kd=4±2 μM）。大规模原子模拟（>100 μs）、SAXS 和 AUC 表明，EGCG-NTD 相互作用具有动态性，且 EGCG 会导致结合态构象中出现一个小比例的紧凑构象。EGCG 与 p53 的相互作用会破坏 p53 与其调节性 E3 连接酶 MDM2 的相互作用，并且在体外泛素化试验中抑制 MDM2 对 p53 的泛素化，可能会稳定 p53 以发挥抗肿瘤活性。我们的工作为 EGCG 的抗癌活性机制提供了深入的了解，并确定 p53 NTD 是通过与小分子的动态相互作用来发现抗癌药物的靶点。
