PPIases
Peptidyl-prolyl cis-trans isomerases (PPIases) are enzymes that accelerate the cis-trans isomerization of peptide bonds preceding proline residues in proteins. This isomerization can be a rate-limiting step in protein folding and conformational changes, helping proteins attain functional structures more rapidly or adjust their activity in response to cellular signals.
PPIases are classified into three major families. Cyclophilins bind the immunosuppressant cyclosporin A and participate in
These enzymes are found throughout the cell, in the cytosol and various organelles, and often function as
Clinically and biologically, PPIases are of interest as therapeutic targets. Inhibitors of cyclophilins and FKBPs are