Human/Mouse/Rat FKBP12 Antibody

FK506 binding protein, 12 kilodalton molecular weight (FKBP12), also called FKBP1, was originally characterized as a peptidyl-prolyl isomerase that catalyzes the transition between cis- and trans-proline residues critical for proper folding of proteins. Proline isomerase activity was demonstrated but not used for quality control. The macrolide immunosuppressants FK506 (Tacrolimus) and rapamycin bind to FKBP12 with high affinity, while the structurally related compound cyclosporine binds with a much lower affinity (1). The binding of these drugs causes FKBP12 to become a potent inhibitor of calcineurin phosphatase activity (2) and TOR kinase activity (3). The inhibition of protein phosphatase activity is highly selective for calcineurin (2), making the FK506/FKBP12 complex a useful tool in the study of this enzyme. Knockout mice lacking FKBP12 are morphologically normal, but develop cardiomyopathies that may be related to dysregulation of ryanodyne receptors (4).