Description
RP2-Serpin-B6 is a polyclonal antibody made to the serine proteinase inhibitor PI-6. The antibody is made to a synthetic peptide based on the reactive center loop area of human serpin-B6. 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.
Use
Serpin-B6, also known as PI-6 (Proteinase Inhibitor-6), PTI (Placental Thrombin Inhibitor), and CAP (Cytoplasmic Antiproteinase) is a serine proteinase inhibitor of the ovalbumin-like B clade of serpins. Serpin-B6 was first discovered as a protein expressed in the placental and which inhibited thrombin. Serpin-B6 also inhibits trypsin, urokinase, plasmin, cathepsin-G and factor Xa. The leukemia cell line K562 also expresses serpin-B6, and mast cells have been shown to produce significant amounts of serpin-B6. Interferon-(gamma) was shown to stimulate serpin-B6 production in mouse hepatocytes. Other tissues express serpin-B6, including heart, brain, skeletal muscle, pancreas, kidney, lung and liver. Oxidation of serpin-B6 inactivated the anti-thrombin activity, and it is thought that thrombin is not the main target for serpin-B6, since the thrombin would be in an oxidizing environment. At the same time, serpin-B6 in not limited to the cytoplasm; even though it does not contain a classical signal sequence, the protein can be found outside the cell. Most of the serpins (SERine Proteinase Inhibitors) are serine proteinase inhibitors, although not all serine proteinase inhibitors are serpins, and visa versa. The overall structural shape of the B clade of serpins most resembles ovalbumin, which is not considered to be a serine proteinase inhibitor. The serpins share a reactive center loop motif: a substrate bait loop which, when cleaved, confers a remarkable molecular shift in the serpin molecule, and traps the enzyme. This mousetrap method works because the uncleaved serpin molecule is in tension, and cleaving the loop allows a more energetically favorable state to exist. The cleavage site in serpin-B6 is Arg341-Cys342 of the 376 amino acid sequence. Several splice variants of serpin-B6 have been identified, most with different aminotermini. The longest serpin-B6 sequence encodes a 409 amino acid protein, with a predicted mass of 46.4 kDa, and a pI of 5.43. The original sequence described was 376 amino acids in length, with predicted mass of 42.6 kDa and pI of 5.16, and isoforms have been reported of 395, 390, and 213 amino acids, with predicted masses of 44.8, 44.0 and 24.6 kDa respectively, and a pIs of 5.38, 5.15 and 5.18. RP2-Serpin-B6 recognizes all of the listed serpin-B6 isoforms. 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.
Storage
The undiluted antibody solution is stable for approximately 12 at -20C.
