Background
Principal Names: Procollagen-proline, 2-oxoglutarate 4-dioxygenase (proline 4-hydroxylase), beta polypeptide Official Gene Symbol: P4HB Gene ID: 5034 (Human) Gene Map Locus: 17q25 (Human). Prolyl 4-hydroxylase (P4-H), an enzyme localized to the endoplasmi reticulum (ER), catalyses the co- and post-translational hydroxylation of proline residues in Xaa-Pro-Gly sequences of collagens and proteins with collagen-like amino acid sequences. Vertebrate P4-H consists of two distinct polypeptides; the catalytically more important, glycosylated alpha-subunit (64 kDa) and the beta-subunit (60 kDa) which belongs to the multifunctional enzyme protein disulphide isomerase (PDI). The beta subunit is a major cellular thyroid hormone-binding protein and shows partial homology with a phosphoinositide-specific phospholipase C, thioredoxins, and the estrogen-binding domain of the estrogen receptor.It catalyzes the formation, breakage and rearrangement of disulfide bonds. It also acts as a chaperone that inhibits aggregation of misfolded proteins in a concentration-dependent manner at high concentrations. Other function of the protein includes its ability to bind thyroid hormone, its role in both the influx and efflux of S-nitrosothiol-bound nitric oxide, and its function as a subunit of the microsomal triglyceride transfer protein complex. The COOH-terminus of the beta subunit has the amino acid sequence Lys-Asp-Glu-Leu, which was recently suggested to be necessary for the retention of a polypeptide within the lumen of the endoplasmic reticulum.

Antigen
BALB/C mice were injected with human prolyl 4-hydroxylase.

Application Notes
We suggest an incubation period of 30 minutes at room temperature. Optimal incubation should be determined by the user based upon the fixation conditions and staining system employed. Pretreatment of formalin fixed paraffin embedded tissue sections before immunohistochemistry has not been characterized. Specificity: This antibody reacts with proteins of 43 kDa and 72-80 kDa molecular weight. It reacts with a surface protein on fibroblasts (synovial, foreskin and thymic), fibroblast cell lines, tissue macrophages, and 95% of peripheral blood monocytes. It does not stain lymphocytes or human epithelial cells but does stain malignant fibrosarcoma tissue. Cellular Localization: Membrane

Reference
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