EGCG binds intrinsically disordered N-terminal domain of p53 and disrupts p53-MDM2 interaction

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, mu M interaction between EGCG and the tumor suppressor p53 (K-D=1.61.4 mu M), with the disordered N-terminal domain (NTD) identified as the major binding site (K-D=4 +/- 2 mu M). Large scale atomistic simulations (>100 mu s), 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. Epigallocatechin gallate (EGCG) is a catechin flavonoid which induces apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Here authors use an interdisciplinary approach to show a direct interaction between EGCG and the tumor suppressor p53 and demonstrate that EGCG inhibits ubiquitination of p53 by MDM2.

Automated summary

Epigallocatechin gallate (EGCG) in green tea induces apoptosis in cancerous cells through a direct interaction with the tumor suppressor p53, inhibiting p53 ubiquitination by its regulatory E3 ligase MDM2 and stabilizing p53 for anti-tumor activity.