Fagus Antibody Services

Recombinant Human SERPINB9/PI-9 Protein (Baculovirus, His Tag)

£585.60£732.00 excluding VAT

SerpinB9; also known as Cytoplasmic antiproteinase 3; CAP-3; Peptidase inhibitor 9; SERPINB9 and PI-9; is a cytoplasm protein which belongs to the serpin family and Ov-serpin subfamily. Serpin-B9 ( CAP-3 / PI-9 ) is the only known human intracellular inhibitor of granzyme B (GrB); the effector molecule in immunity against cytomegalovirus (CMV) and in renal allograft rejection. Serpin-B9 and SPI-6 expression in immune-privileged cells; APCs; and CTLs protects these cells against the actions of granzyme B; and when expressed in tumor cells or virally infected hepatocytes; confers resistance to killing by CTL and NK cells. Expression of increasing levels of Serpin-B9 ( CAP-3 / PI-9 ) in target cells may progressively inhibit immune surveillance by blocking NK and CTL-induced cytotoxicity through the perforin / granzyme pathway and then through the Fas / FasL pathway. Serpin-B9 ( CAP-3 / PI-9 ) is selectively up-regulated in hepatocytes in response to infiltration of the liver by NK cells that express perforin and enzymatically active granzyme B. Upregulated expression of Serpin-B9 ( CAP-3 / PI-9 ) in NSCLC cells may serve to protect them from apoptosis induced by GrB.



Active Protein
Protein Construction

A DNA sequence encoding the human SERPINB9 (P50453) (Glu 2-Pro 376) was expressed; with a polyhistidine tag at the N-terminus.


Glu 2-Pro 376

Fusion Tag






Expressed Host

Baculovirus-Insect Cells


This product is provided as lyophilized powder which is shipped with ice packs.


> 97 % as determined by reducing SDS-PAGE.


< 1.0 EU per µg of the protein as determined by the LAL method.

Stability and Storage

Generally, lyophilized proteins are stable for up to 12 months when stored at -20 to -80℃. Reconstituted protein solution can be stored at 4-8℃ for 2-7 days. Aliquots of reconstituted samples are stable at < -20℃ for 3 months.

Mol Mass

44.5 kDa

AP Mol Mass

43 kDa


Lyophilized from sterile 50mM Tris, 100mM NaCl, pH 7.4

Research Areas

Cell biology, immunology


Please refer to the printed manual for detailed information.

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