Protein disulfide isomerase (PDI) from bovine liver is a homodimer with a molecular weight of 107 kDa with the monomer corresponding to 57 kDa. The isoelectric point (pI) is approximately 4.2. The enzyme is a glycoprotein with 12% total carbohydrate content comprising of mannose, galactose, N-acetyl neuraminic acid (NANA) and 2-acetamido-2-deoxyglucose. PDI is an ubiquitous redox chaperone enzyme. It belongs to the, thioredoxin superfamily and is high conserved.
Protein Disulfide Isomerase (PDI) is mainly located in the endoplasmic reticulum (ER), where it assists in protein-folding and thiol-disulfide exchanges. It aids protein refolding in vitro allowing recombinant proteins to achieve their native state.