Ansamycins, including geldanamycin and the derivative 17-allylamino-17- demethoxygeldanamycin, and radicicol are known for their ability to tightly bind to the ATP- binding site of the amino-terminal domain region of heat shock protein 90. We have found that geldanamycin and some of its derivatives can inhibit hepatocyte growth factor/scatter factor-mediated Met tyrosine kinase receptor-dependent urokinase-plasminogen ...