DESIGN, SYNTHESIS, AND KINETIC EVALUATION OF HIGH-AFFINITY FKBP LIGANDS AND THE X-RAY CRYSTAL-STRUCTURES OF THEIR COMPLEXES WITH FKBP12.

The design and synthesis of high-affinity FKBP12 ligands is described. These compounds potently inhibit the cis-trans-peptidylprolyl isomerase (rotamase) activity catalyzed by FKBP12 with inhibition constants (K i,app ) as low as 1 nM, yet they possess remarkable structural simplicity relative to FK506 and rapamycin, from which they are conceptually derived. The atomic structures of three FKBP12-ligand complexes and of one unbound ligand were determined by X-ray crystallography and are compared to the FKBP12-FK506 and FKBP12-rapamycin complexes