The in-tandem application of qXL-MS and IC-FPOP to evaluate the inhibition of HSP90 by tanespimycin

Though healthy cells utilize the function of the 90 kDa heat shock protein (HSP90) to control cell growth, cell survival, and development -particularly in response to cellular stress- the activity of this protein is also beneficial to the growth and survival of cancer cells. Tanespimycin (17-AAG) is a well-characterized HSP90 inhibitor that has been shown to be cytotoxic to cancer cells. The complementary structural information gained from quantitative crosslinking with mass spectrometry (qXL-MS) and the In-Cell Fast Photochemical Oxidation of Proteins (IC-FPOP) was used to investigate the inhibition of HSP90 by 17-AAG in MCF-7 breast cancer cells.