Protein phosphatases dephosphorylate a number of critical cellular regulators to promote or inhibit their activity. Calcineurin (protein phosphatase 2B) is a protein phosphatase involved in T cell activation and is specifically inhibited by the immunosuppressive drugs, cyclosporin A and FK506 (tacrolimus). The immunosuppressive activity of cyclosporins has been correlated with their ability to form complexes with cyclophilins that inhibit calcineurin phosphatase activity and prevent incorporation of cyclophilin into viral particles. Similarly, FK506 binds to FKBP12 causing it to become a potent inhibitor of calcineurin phosphatase activity. R&D Systems currently offers recombinant human Cyclophilin A (Catalog # 3589-CA), recombinant human Calcineurin (Catalog # 3160-CA), and recombinant human FKBP12 (Catalog # 3777-FK) for the study of calcineurin phosphatase activity. The activities of Cyclophilin A and FKBP12 were measured by their ability to inhibit calcineurin phosphatase activity in the presence of either Cyclosporin A or FK506, respectively.
|Table 1. R&D Systems Enzymes
|Recombinant Enzyme||Catalog #|
|Human Cyclophilin A||3589-CA|
Note: The enzymes, immunosuppressive agents, and dilutions of each vary depending on the enzyme that is being assayed. Consult the specific assay protocol for the dilutions that should be used in each assay.
|Recombinant Enzyme||Alternate Name||Catalog #||Drug/Co-factor|
|Human Cyclophilin A||PPIA, CYPA, CYPH||3589-CA||Cyclosporin A|