Western blot analysis of extracts from HEK293 cells, untreated or treated with indicated concentrations of Geldanamycin for 20 hours, using IKKα Antibody #2682 showing IKKα degradation (upper). β-Actin Antibody #4967 was used as a loading control (lower).
Structure of Geldanamycin
Geldanamycin is supplied as 600 μg powder. Store at or below -20ºC. Before usage, dissolve the chemical in 1.08 ml DMSO to make 1 mM Geldanamycin. For working concentrations of 300 nM-1 μM, dilute 1:3000 to 1:1000. Treat cells with the desired concentration for 20-48 hours. Store liquid form at or below -20ºC.
Store lyophilized or in solution at -20ºC, desiccated. Protect from light. In lyophilized form, the chemical is stable for 24 months. Once in solution, use within 1 week to prevent loss of potency. Aliquot to avoid multiple freeze/thaw cycles.
Geldanamycin (GA) is a naturally existing HSP90 inhibitor that belongs to the benzoquinone ansamycin family. GA binds to the amino terminal ATP-binding pocket of HSP90 and inhibits ATP binding and hydrolysis. HSP90 is a chaperone interacting with a wide variety of important target proteins for cell signaling and regulation during tumorgenesis (1,2). The binding of GA to HSP90 interferes with HSP-mediated target protein folding, leading to target aggregation and degradation (1-3). GA and its synthetic derivatives show higher affinity to HSP90 in tumor cells as compared to normal tissues and constitute a class of protential antitumor drugs (2-3).
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