Recombinant Human Prolyl 4-Hydroxylase Subunit β/P4HB is produced with our E. coli expression system. The target protein is expressed with sequence (Asp18-Lys505) of Human P4HB fused with a 6His tag at the C-terminus. Protein Disulfide-Isomerase (P4HB) is an endoplasmic reticulum lumen protein that belongs to the protein disulfide isomerase family. P4HB contains two thioredoxin domains and catalyzes the formation, breakage, and rearrangement of -S-S- bonds in proteins. P4HB is involved in hydroxylation of prolyl residues in preprocollagen. P4HB has the ability to act as a chaperone that inhibits aggregation of misfolded proteins in a concentration-dependent manner. P4HB plays a role in both the influx and efflux of S-nitrosothiol-bound nitric oxide.