FKBP12 F36V (mutant form of FKBP12, FK506-binding protein 1A) (FKBP12¹F36V (or FKBP12(F36V)))

FKBP12 F36V is an engineered point mutant (phenylalanine 36 to valine) of the human FKBP12 protein (FK506-binding protein 1A, a 12 kDa peptidyl-prolyl isomerase). The F36V substitution creates a hydrophobic specificity pocket that enables high-affinity binding (low/sub-nanomolar) to synthetic ligands with "bump" substituents, which do not bind wild-type FKBP12. This mutant is widely used as a fusion tag in chemical biology for rapid, selective control of tagged proteins, including degradation via PROTAC/dTAG systems (recruiting CRBN or VHL E3 ligases), fluorescent labeling in live cells, stabilization of destabilizing domains (e.g., with Shield-1/2), and inducible dimerization (e.g., AP1903 for apoptosis in gene therapy). It supports applications in target validation for oncoproteins like KRASG12V, BRD4, and EWS/FLI, with degradation often occurring within 1 hour

Other names

F36V-FKBPFKBP12¹WT (distinguished from wild-type)FKBP(F36V)FKBP*

Recruitment of E3 ubiquitin ligases (CRBN or VHL) for targeted protein degradation (in dTAG system); Stabilizing ligand binding to prevent proteasomal degradation (in destabilizing domains); Fluorescent labeling for imaging; Dimerization for signaling activation (e.g., apoptosis induction)