PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. [protein]-peptidylproline (omega=180) = [protein]-peptidylproline (omega=0) Binds cyclosporin A (CsA). CsA mediates some of its effects via an inhibitory action on PPIase (By similarity). Ubiquitous, with highest levels in flowers and lowest levels in roots. By wounding, and slightly by light. Belongs to the cyclophilin-type PPIase family.