Recombinant Bovine Peptidyl-Prolyl Cis-Trans Isomerase B (PPIB)

Bovine peptidyl-prolyl cis-trans isomerase B (PPIB), also known as cyclophilin B, is an enzyme that belongs to the cyclophilin family of peptidyl-prolyl cis-trans isomerases (PPIases). These enzymes catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides, which is an essential step in protein folding. PPIB is involved in the folding of proteins, particularly in the endoplasmic reticulum (ER), and plays a role in the proper formation of disulfide bonds, which are crucial for the correct structure and function of many proteins. In the Bovine, PPIB contributes to protein homeostasis and is important for the survival of cells, particularly in the context of secretory proteins like insulin, where proper folding is essential for biological activity. Disruptions in PPIB function can lead to ER stress and apoptosis, as seen in studies where inhibition of PPIB mediates cyclosporin A-induced apoptosis of islet β cells.