Rabbit Antibody to HAI-2 (HGFA (Hepatocyte Growth Factor Activator) Inhibitor-2, Placental Bikunin, SPINT2); Between KD1 and KD2

RP1-HAI-2 is a rabbit polyclonal antibody made to the region between Kunitz Domain-1 and Kunitz Domain-2 of human HAI-2. The antibody is made to a synthetic peptide based on the human sequence, and will recognize HAI-2 and not HAI-1.  The antibody has been peptide-affinity purified, concentrated to 1 mg/ml, with the addition of 0.05% Sodium Azide as preservative, and 50% glycerol as cryoprotectant.

HAI-2 is an endogenous inhibitor of the kunitz-type serine proteinase HGF-activator (HGFA). HGF was first described as a hepatocyte-specific mitogen and survival factor, and has since been shown to exert a variety of actions on many cell types by binding to its MET receptor. HGF is activated by cleavage of the single-chain form to form a two-chain version by HGFA. HAI-2 also inhibits trypsin, and MTSP-1 (Matriptase-1), a serine proteinase that also activates HGF, and HGF-2 has been shown to inhibit hepsin with nanamolar kIs. HAI-2 was first known as bikunin, and SPINT2 (Serine Proteinase Inhibitor-2), a proteinase inhibitor found in amniotic fluid. HAI-2 message predicts a protein of 252 amino acids, with a predicted mass of 28.23 kDa and a pI of 9.54. A protein termed HAI-2 related small protein is a 106 amino acid protein with little homology to HAI-2, and the HAI-2 antibodies do not recognize the HAI-2 RSP. The HAI proteins are glycosylated, and may have other post-translational modifications, thus the apparent molecular weight is 22-32 Kda kDa for the full-length HAI-2. The chondroitin sulfate groups attached to HAI-2 are thought to be important for its function. The HAI-2 antibodies do not recognize HAI-1. Mice treated with HAI-2 in an ovarian cancer model had smaller tumors, and HAI-2 is reported to be elevated in macrophages during ovarian cancer, and this is considered a favorable indicator of survival. HAI-2 is secreted and membrane-inserted via a type-I  transmembrane domain. The carboxyterminal end is a cytoplasmic domain, thought to interact with signaling and cytoskeletal machinery. The extracellular domains include two kringle domains (KD1 and KD2), and KD2 is thought to be inactive or with much lower activity against HGF.  In mice the dominant HAI-2 lacks the first kringle domain, but the two-domain form dominates in humans, although in human testis a shorter HAI-2 has been reported, using a second transcription site. HAI-2 is shed from the cell surface by cleavage extracellular to the transmembrane domain. A recommended starting concentration for Western blots is 1:1000 when using colorimetric substrates such as BCIP/NBT, and 1:5000 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 12 months at -20°C.

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