Anti-NSCLC activity in vitro of Hsp90 N inhibitor KW-2478 and complex crystal structure determination of Hsp90 N -KW-2478.
Li, H.J., Wang, Q.S., Han, W., Zhou, H., Li, P., Zhou, F., Qin, W., Zhao, D., Zhou, X., He, C.X., Xing, L., Li, P.Q., Jin, X., Yu, F., He, J.H., Cao, H.L.(2021) J Struct Biol 213: 107710-107710
- PubMed: 33610655 
- DOI: https://doi.org/10.1016/j.jsb.2021.107710
- Primary Citation of Related Structures:  
6LT8 - PubMed Abstract: 
KW-2478 is a promising anti-cancer lead compound targeting to the molecular chaperone heat shock protein 90 N (Hsp90 N ). Absence of complex crystal structure of Hsp90 N -KW-2478, however, hampered further structure optimization of KW-2478 and understanding on the molecular interaction mechanism. Herein, a high-resolution complex crystal structure of Hsp90 N -KW-2478 was determined by X-ray diffraction (XRD, resolution limit: 1.59 Å; PDB ID: 6LT8) and their molecular interaction was analyzed in detail, which suggested that KW-2478 perfectly bound in the N-terminal ATP-binding pocket of Hsp90 to disable its molecular chaperone function, therefore suppressed or killed cancer cells. The results from thermal shift assay (TSA, ΔTm, 18.82 ± 0.51 °C) and isothermal titration calorimetry (ITC, K d , 7.30 ± 2.20 nM) suggested that there is an intense binding force and favorable thermodynamic changes during the process of KW-2478 binding with Hsp90 N . Additionally, KW-2478 exhibited favorable anti-NSCLC activity in vitro, as it inhibited cell proliferation (IC 50 , 8.16 μM for A549; 14.29 μM for H1975) and migration, induced cell cycle arrest and promoted apoptosis. Thirty-six novel KW-2478 derivatives were designed, based on the complex crystal structure and molecular interaction analysis of Hsp90 N -KW-2478 complex. Among them, twenty-two derivatives exhibited increased binding force with Hsp90 N evaluated by molecular docking assay. The results would provide new guidance for anti-NSCLC new drug development based on the lead compound KW-2478.
Organizational Affiliation: 
Shaanxi Key Laboratory of Ischemic Cardiovascular Disease, Institute of Basic & Translational Medicine, Xi'an Medical University, Xi'an 710021, China.