Heat Shock Protein Inhibitor II

Heat shock protein (Hsp) inhibitor II is the active form of Hsp inhibitor I and a benzylidene lactam compound that prevents the synthesis of inducible Hsps, such as Hsp105, Hsp72, and Hsp40. Hsp inhibitor II decreases Hsp72 synthesis in vivo and reduces thermotolerance of tumors in SCC VII tumor-containing mice. At 100 μM, it inhibits the development of thermotolerance in COLO 320 DM cells. Inhibition of Hsp70 with Hsp inhibitor II in combination with amphotericin B (AmB; ) increases susceptibility of AmB-susceptible (MICs = 0.058 versus 0.27 μg/ml for combined and AmB alone, respectively) and AmB-resistant (MICs = 21.33 versus >32 μg/ml for combined and AmB alone, respectively) strains of A. fumigatus.

KNK423 is a specific heat shock protein (HSP) synthesis inhibitor. KNK423 improves the efficiency of Amphotericin B in inhibiting resistant Aspergillus terreus by blocking HSP70. KNK423 can be used in cancer and bacterial infection research[1][2].

[1] Koishi M, et al. The effects of KNK437, a novel inhibitor of heat shock protein synthesis, on the acquisition of thermotolerance in a murine transplantable tumor in vivo. Clin Cancer Res. 2001 Jan;7(1):215-9. PMID:11205912
[2] Blatzer M, et al. Blocking Hsp70 enhances the efficiency of amphotericin B treatment against resistant Aspergillus terreus strains. Antimicrob Agents Chemother. 2015 Jul;59(7):3778-88. DOI:10.1128/AAC.05164-14