Fig. 1.

Steady-state fluoresce quenching assay. a. The binding pocket of FK1 with the W90 residue shown in yellow sticks. b. Fluorescence emission spectra of FKBP51 and rapamycin resulting from excitation at 295 nm. The fluorescence intensity spectra of the FK1 domain (20 μM) and rapamycin (100 μM) alone are shown in red and purple, respectively. The green curve represents the fluorescence intensity spectra of 20 μM FK1 titrated with 100 μM rapamycin. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)