Rabbit Antibody to PC4 (paired basic amino acid cleaving enzyme-4, PC4, PCSK4, Neuroendocrine Convertase-3); Homo-B domain

RP2-PC4 is a rabbit polyclonal antibody made to the subtilisin-like serine protease PC4.   The antibody is made to a synthetic peptide based on the Homo-B domain of human PC4. The antibody has been peptide-affinity purified, concentrated to 1.0 mg/ml, with the addition of 0.05% sodium azide as preservative and 50% glycerol as cryoprotectant.

PC4 was the fifth of the human prohormone convertasae enzymes to be discovered. Like furin, PC1, PC2 and PACE4, PC4 is a serine proteinase that cleaves after pairs of basic amino acids, but with some differences in substrate specificity and distribution. The catalytic domain has homology to other PC enzymes, the prohormone convertase family initially discovered for their role in processing POMC, insulin and other pro-hormones, and later found to process a wider range of precursor proteins. Some have renamed the prohormone convertases as proprotein convertases, and another group has renamed the entire family with a uniform nomenclature of SPCs ( s ubtilisin-like p roprotein c onvertases). PC4 structure contains a propeptide domain, a catalytic domain and an RGD containing cystein-rich domain (homo-B). The PCs have an RxxR consensus cleavage requirement, and the propeptide is separated from the mature protein by just such a sequence. After cleavage of the propeptide domain, PC4 becomes a two-chain form, and the propeptide piece is released after a second internal cleavage. PC4 is thought to be anchored to the plasma membrane via a GPI anchor, and can be shed from the cell surface.   PC4 was first thought to be testis specific, and null mutant mice were found to have reduced activity and decreased fertility. The female null mutants also showed reduced fertility when mated against wild type mice, and PC4 was found in the ovary. PC4 has been shown to process PACAP (pituitary adenylate cyclase-activating polypeptide), and is thought to be the main processing enzyme for PACAP. The message for PC4 encodes a 755 amino acid protein with a predicted mass of 82.79 kDa, and a pI of 9.46, and this quite basic pI is likely to influence localization and function of PC4. Shed PC4 is seen as a 54 kDa band on   reduced Western blots, with smaller bands seen as the PC4 is further processed. A shorter sequence that encodes a 242 amino acid form is reported, with a predicted mass of 26.12 kDa and a pI of 9.57. This shorter sequence starts at a methionine 504 amino acids downstream from the long form of PC4, just past the RGD sequence, but it is unclear if this message produces a viable protein. A recommended starting concentration for Western blots is 1:1,000 when using colorimetric substrates such as BCIP/NBT, and 1:5,000 for chemiluminescent substrates.

FOR RESEARCH USE ONLY. NOT FOR USE IN HUMANS.

The undiluted antibody solution is stable for 12 months at -20 ° C.

Triple Point Biologics products are sold exclusively through Abcam. For availability, pricing and buying information please select your country below and press 'Go'. You will be relocated to the relevant datasheet page on Abcam's website.