The specific activity, determined by measuring the enzyme's ability to cleave 1 µmole of suc-AAFP-pNA per minute at 37°C in Tris-Hcl pH 8.0 using chymotrypsin as a reference, is greater than 900 nmoles/min/mg.
FKBP3 is characterized by its peptidyl-prolyl cis-trans isomerase (PPIase) activity, which facilitates protein folding by catalyzing the isomerization of proline residues in polypeptides . This activity is crucial for the proper folding and function of many proteins within the cell.
In addition to its PPIase activity, FKBP3 has been found to play a role in various cellular processes, including:
One of the most notable functions of FKBP3 is its role in immunosuppression. When bound to FK506, FKBP3 forms a complex that inhibits the phosphatase activity of calcineurin . This inhibition prevents the activation of the nuclear factor of activated T-cells (NF-AT), thereby blocking T-cell activation and proliferation. This mechanism is particularly important in preventing organ rejection in transplant patients and in treating autoimmune disorders .
FKBP3 and other members of the FKBP family have become subjects of considerable interest in various fields of research due to their involvement in numerous cellular and molecular pathways . Some key areas of research and therapeutic applications include: