Download MendeleyStructural Basis for Design of New Purine-Based Inhibitors Targeting the Hydrophobic Binding Pocket of Hsp90.
Shin, S.C., El-Damasy, A.K., Lee, J.H., Seo, S.H., Kim, J.H., Seo, Y.H., Lee, Y., Yu, J.H., Bang, E.K., Kim, E.E., Keum, G.(2020) Int J Mol Sci 21
- PubMed: 33317068
- DOI: https://doi.org/10.3390/ijms21249377
- Primary Citation of Related Structures:
7D1V, 7D22, 7D24, 7D25, 7D26 - PubMed Abstract:
Inhibition of the molecular chaperone heat shock protein 90 (Hsp90) represents a promising approach for cancer treatment. BIIB021 is a highly potent Hsp90 inhibitor with remarkable anticancer activity; however, its clinical application is limited by lack of potency and response. In this study, we aimed to investigate the impact of replacing the hydrophobic moiety of BIIB021, 4-methoxy-3,5-dimethylpyridine, with various five-membered ring structures on the binding to Hsp90. A focused array of N 7 / N 9 -substituted purines, featuring aromatic and non-aromatic rings, was designed, considering the size of hydrophobic pocket B in Hsp90 to obtain insights into their binding modes within the ATP binding site of Hsp90 in terms of π-π stacking interactions in pocket B as well as outer α-helix 4 configurations. The target molecules were synthesized and evaluated for their Hsp90α inhibitory activity in cell-free assays. Among the tested compounds, the isoxazole derivatives 6b and 6c , and the sole six-membered derivative 14 showed favorable Hsp90α inhibitory activity, with IC 50 values of 1.76 µM, 0.203 µM, and 1.00 µM, respectively. Furthermore, compound 14 elicited promising anticancer activity against MCF-7, SK-BR-3, and HCT116 cell lines. The X-ray structures of compounds 4b , 6b , 6c , 8 , and 14 bound to the N -terminal domain of Hsp90 were determined in order to understand the obtained results and to acquire additional structural insights, which might enable further optimization of BIIB021.
Organizational Affiliation:
Biomedical Research Institute, Korea Institute of Science and Technology (KIST), Hwarangro 14-gil 5, Seongbuk-gu, Seoul 02792, Korea.
