Rabbit Antibody to Kallikrein-3 (Prostate Specific Antigen (PSA), APS); Catalytic domain  

RP2-hK3 is a rabbit polyclonal antibody made to the serine proteinase kallikrein-3 (PSA, hK3).  The antibody is made to a synthetic peptide based on the catalytic domain of human Kallikrein-3.  RP2-hK3 reacts with human Kallikrein-3, and does not react with the human kallikreins (hK1, 3-15), although hK2 can be detected in slightly.  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.

Kallikrein-3, also known as Prostate Specific Antigen (PSA) was first discovered as a major protein in semen, and determined to be a prostate-specific protein. Since then, other tissues and bodily fluids have been shown to contain Kallikrein-3, but at much lower levels than in seminal plasma. Kallikrein-3 is a serine proteinase with trypsin-chymotrypsin specificities, thought to be important in liquefying clots in semen. The active site has a catalytic triad of His-Asp-Ser, with the serine in a Gly-X-Ser-X-Gly arrangement. The utility of Kallikrein-3 as a prostate-specific marker has allowed its use for assays of prostate cancer. Both Kallikrein-3 and Kallikrein-2 are produced by the prostate, but the blood-testis barrier usually keeps the circulating levels low. Prostate tumors or benign prostate hyperplasia give Kallikrein-3 access to normal circulation, and measurement of the PSA levels is a reasonable indicator of the amount of access. It was thought that Kallikrein-3 was responsible for allowing or making the tumor cells to spread aggressively, but it is still unclear what if any role Kallikrein-3 plays in tumor biology. Pre-pro-kallikrein-3 is processed to a 237 amino acid long active enzyme, with amino terminal sequence IVGGWE. Kallikrein-3 forms complexes with and is inhibited by a number of endogenous proteinase inhibitors, including α1-Protienase Inhibitor and protein C inhibitor.The full length message for Kallikrein-3 encodes a protein of 261 amino acids, with a predicted mass of 28.74 kDa and a pI of 8.27. Gllcosylation and other post translational modifications make the apparent weight on SDS PAGE gels 32-33 kDa, The pI is significantly more basic than for Kallikrein-1 and Kallikrein-2, which have predicted pI of 4.54 and 6.49, respectively.  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.  Higher concentrations of antibody may be needed for samples from more distantly related species.  

FOR RESEARCH USE ONLY. NOT FOR USE IN HUMANS.

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

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