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Recombinant Human FGL2 His-tag Protein, CF

Bio-Techne includes R&D Systems | Catalog # 10303-FL

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Product Specifications


Chinese Hamster Ovary cell line, CHO-derived human FGL2 protein
Asp32-Pro439, with a C-terminal 6-His tag


>80%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.

Endotoxin Level

<0.10 EU per 1 μg of the protein by the LAL method.

N-terminal Sequence Analysis


Predicted Molecular Mass

48 kDa


52-79 kDa, under reducing conditions.


Measured by its ability to inhibit anti-CD3-induced proliferation of stimulated human T cells.

The ED50 for this effect is 1-8 μg/mL.

Scientific Data Images for Recombinant Human FGL2 His-tag Protein, CF

Recombinant Human FGL2 His-tag Protein Bioactivity

Recombinant Human FGL2 His-tag Protein Bioactivity

Recombinant Human FGL2 His-tag (Catalog # 10303-FL) inhibits anti-CD3-induced proliferation of stimulated human T cells. The ED50 for this effect is 1-8 μg/mL.

Formulation, Preparation and Storage

Formulation Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
Reconstitution Reconstitute at 500 μg/mL in PBS.
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: FGL2

FGL2 (fibrinogen-like protein 2), also called fibroleukin, is a 64-70 kDa secreted glycoprotein of the Fibrinogen-like superfamily. It has prothrombinase activity and also promotes T regulatory (Treg) activity (1-6). The human FGL2 gene encodes a 439 amino acid (aa) protein that contains a 23 aa signal sequence and a 416 aa mature sequence with a coiled-coil region and a fibronectin C-terminal homology domain or FRED (1, 2). A 260-280 kDa FGL2 complex is thought to be a tetramer formed by covalent disulfide linkage of dimers that are associated via coiled-coil interactions (2, 3). Mature human FGL2 shares 79% aa identity with mouse and rat FGL2. FGL2 appears to have two modes of action. One mode involves its prothrombinase activity, which requires calcium and acidic phospholipids (4). This mode is thought to be active during hepatitis viral infections when FGL2, produced by macrophages in response to IFN-gamma, induces hepatic apoptosis and fibrin deposition (7). In addition, FGL2 produced by endothelial cells in response to TNF-alpha within cardiac xenografts or allografts promotes coagulation during acute vascular rejection (7-9). A second mode of action involves soluble (not phospholipid-associated) FGL2 and is independent of prothrombinase activity (2). Soluble FGL2 is required for Treg function, and directly suppresses DC, T, and B cell immune reactivity; consequently, some FGL2-deficent mice develop autoimmune glomerulonephritis (5, 6). In vitro, soluble FGL2 can skew T cell polarization toward Th2 and inhibit proliferation of stimulated T cells and maturation of DC (6). In pregnancy, fetal trophoblast cells secrete FGL2. The immune suppressive mode of FGL2 may prevent early fetal loss; however, the procoagulant mode is thought to mediate infection-triggered abortion (10). In the central nervous system (CNS), FGL2 was shown to be highly expressed in glioma stem cells and primary glioblastoma cells and may serve as a critical immune oncology target (11).


  1. Koyama, T. et al. (1987) Proc. Natl. Acad. Sci. USA 84:1609.
  2. Marazzi, S. et al. (1998) J. Immunol. 161:138.
  3. Olson, G. E. et al. (2004) J. Biol. Chem. 279:51266.
  4. Chan, C. W. Y. et al. (2002) J. Immunol. 168:5170.
  5. Shalev, I. et al. (2008) J. Immunol. 180:249.
  6. Chan, C. W. Y. et al. (2003) J. Immunol. 170:4036.
  7. Liu, M. et al. (2006) J. Immunol. 176:7028.
  8. Mendicino, M. et al. (2005) Circulation 112:248.
  9. Ning, Q. et al. (2005) J. Immunol. 174:7403.
  10. Clark, D. A. et al. (2004) Mol. Hum. Reprod. 10:99.
  11. Yan J. et al. (2019) Nat Commun. 10:448.

Long Name

Fibrinogen-like 2

Alternate Names

Fibroleukin, T49

Entrez Gene IDs

10875 (Human); 14190 (Mouse); 84586 (Rat); 102123631 (Cynomolgus Monkey)

Gene Symbol



Additional FGL2 Products

Product Documents for Recombinant Human FGL2 His-tag Protein, CF

Certificate of Analysis

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Note: Certificate of Analysis not available for kit components.

Product Specific Notices for Recombinant Human FGL2 His-tag Protein, CF

For research use only