Description
RP2-Serpin-B1 is a polyclonal antibody made to the serine proteinase inhibitor leukocyte elastase inhibitor (LEI). The antibody is made to a synthetic peptide based on the reactive center loop area of human serpin-B1. 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-B1, also known as LEI (Leukocyte Elastase Inhibitor), M/NEI Monocyte/Neutrophil Elastase Inhibitor), and EI (Elastase Inhibitor) is a serine proteinase inhibitor of the ovalbumin-like B clade of serpins. Serpin-B1 was first discovered in monocytes and neutrophils, and given the name elastase because of the ability to inhibit neutrophil elastase at low nanamolar efficiency. Serpin-B1 also inhibits pancreatic elastase, cathepsin-G and proteinase-3. The broad specificity is conferred by two residues in the reactive center loop: Cys344 for elastases, and Phe343 for chymotrypsin-like enzymes. In animal models of Cystic Fibrosis, recombinant serpin-B1 blocked much of the damage that the elevated levels of neutrophil elastase, cathepsin-G and proteinase-3 cause, suggesting that serpin-B1 might be used therapeutically in CF patients. Most of the serpins (SERine Proteinase Inhibitors) are serine proteinase inhibitors, although not all serine proteinase inhibitors are serpins, and visa versa. Serpin-B1 is a B-clade serpin, due to the overall topological similarity to ovalbumin, although ovalbumin 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 full length serpin-B1 sequence encodes a 379 amino acid protein, with a predicted mass of 42.7 kDa, and a pI of 5.85. Glycosylation makes serpin-B1 run closer to 47 kDa on reduced Western blots, and a 66 kDa complex is formed with elastase, stable to SDS and reduction. 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.
