Protein disulfide-isomerase (P4HB)

This multifunctional protein catalyzes the formation, breakage and rearrangement of disulfide bonds. At the cell surface, seems to serve as a reductase which cleaves disulfide bonds of proteins attached to the cell.

May therefore cause structural modifications of exofacial proteins. Within the cell, seems to form/rearrange disulfide bonds of nascent proteins.