Assays for detection of bioactive compounds that interact with heat shock protein 90

A method for identifying a candidate molecule as having activity as an inhibitor of Hsp90, comprising the steps of

• (a) adding the candidate molecule to a population of test cells, wherein said test cells exhibit an Hsp90-dependent activity in the absence of the candidate compound;
• (b) incubating the cells for a period of time sufficient to permit growth of the cells and exhibit the Hsp90-dependent activity in the absence of an effective inhibitor;
• (c) determining the amount of the Hsp90-dependent activity;
• and
• (d) comparing the determined amount of Hsp90-dependent activity to a standard value determined for the test cells in the absence of an effective inhibitor, wherein a determined value of the Hsp90-dependent activity that is lower than the standard value by a statistically significant amount is indicative that the candidate molecule has activity as an in vivo inhibitor of Hsp90.

A compound comprising

• (a) a binding moiety;
• and
• (b) a fluorescent moiety;
• wherein the compound binds, via the binding moiety to Hsp90, and the fluorescent moiety has polarized fluorescence when the compound is bound to Hsp90, and fluorescence with a lesser degree of polarization when the compound is not bound to Hsp90.