PPIases accelerate the folding of proteins. It catalyzes the cis-trans isomerization of proline imid ic peptide bonds in oligopeptides. Thought to function as a catalyst in the folding and modification of cuticle collagens (By similarity). [protein]-peptidylproline (omega=180) = [protein]-peptidylproline (omega=0) Belongs to the cyclophilin-type PPIase family.