SERPINB9 (Serine/Cysteine Proteinase Inhibitor, Clade B, Member 9, Serpin B9, PI9, Cytoplasmic Antiproteinase 3, CAP-3, CAP3)

PI-9 (proteinase inhibitor 9), also known as SerpinB9, is a 42kD intracellular nucleocytoplasmic serpin expressed in cytotoxic lymphocytes (CTLs), natural killer (NK) cells, monocyte-derived dendritic cells (DCs), and to a lesser extent in B cells and myeloid cells.\n\nGranzyme B (grB) is a serine protease highly expressed by CTLs and NK cells, which is endocytosed by virus-infected and malignant target cells. The subsequent release of grB from the endocytic vesicles into the cytoplasm of the target cells, triggers grB-mediated apoptosis, through cleavage of various cytoplasmic or nuclear proteins. PI-9, up-regulated in response to grB production and degranulation, has been identified as a potent inhibitor of Granzyme B-mediated apoptosis, providing a vital self-protection mechanism against the premature apoptosis of CTLs and NK cells by grB, which may escape into the cytoplasm of the effector cells themselves.\n\nApplications:\nSuitable for use in Flow Cytometry, Immunohistochemistry (paraffin), and Western Blot. Other applications not tested. \n\nRecommended Dilution:\nFlow Cytometry: 1:10-1:100\nImmunohistochemistry (paraffin): 1:50\nOptimal dilutions to be determined by the researcher. \n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.

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SPECIFICATIONS

Catalog Number

S1000-89A

Size

100ug

Applications

FC, IHC, WB

Hosts

Mouse

Reactivities

Hum

Form

Supplied as a liquid in PBS, 0.05% sodium azide.

P Type

Mab

Purity

Purified by Protein G affinity chromatography.

Isotype

IgG1

References

1. Hirst, C.E. et al. (2001) Perforin-independent expression of granzyme B and proteinase inhibitor 9 in human testis and placenta suggests a role for granzyme B-mediated proteolysis in reproduction. Mol. Hum. Repro. 7: 1133-1142. 2. Hirst, C.E. et al. (2003) The intracellular granzyme B inhibitor, proteinase inhibitor 9, is up-regulated during accessory cell maturation and effector cell degranulation, and its overexpression enhances CTL potency. J. Immunol. 170: 805-815.

Additional Info

Recognizes human PI-9 at ~42kD under reducing conditions. Does not react with porcine or mouse PI-9.