Application of targetted covalent drug design method towards the design of Hsp90 CTD covalent inhibitors

Hsp90 (Heat shock protein 90) is an inductive molecular chaperone that governs the correct protein folding to resist environmental stress. It has been a promising anti-cancer drug target significantly overexpressed by cancer cells (up to 55.6%). However, currently, there is no approved drug of this type due to the high toxicity and harmful heat shock response found in Hsp90 NTD (N-terminus domain) inhibitors. In recent decades, the Hsp90 CTD (C-terminus domain) inhibitor is an excellent alternative to Hsp90 NTD inhibitors, triggering no heat shock response. Nevertheless, the lack of a drug-protein co-crystal structure limited its development and created a gap between detailed structural activity data and clinical trials. There is no Hsp90 CTD inhibitor has entered any clinal trials due to lack of drug potency.