Background:

IC50: 5 nM for F36V-FKBP in competition fluorescence polarization assay

FKBP ligand homodimers can be used to trigger signaling events inside cells and animals that have been engineered to express fusions between and FKBP appropriate signaling domains. However, use of these dimerizers in vivo is potentially limited by ligand binding to endogenous FKBP. AP1903 is a homodimer of the modified ligand for FKBP.

In vitro: By selective inhibition of FKBP, AP1903 elicited potent and dose-dependent apoptotic death of the human fibrosarcoma line HT1080 engineered cells in culture, with an EC50 of