SFRP1, Recombinant, Human (Secreted Frizzled Related Protein 1, SARP2, FrzA)

Secreted Frizzled Related Proteins (sFRPs) are a family of secreted, soluble vertebrate glycoproteins which contain homology to the Wnt-binding domain of the Frizzled (Fz) family of transmembrane receptors. sFRPs are ~30-35kD in size and are comprised of 3 domains: a signal sequence; an N-terminal Fz cysteine-rich domain (CRD) with 10 conserved cysteines; and a C-terminal heparin-binding region with weak homology to Netrin. The Fz CRD mediates Wnt-binding and is present in all Fz and sFRP family members (1). sFRP-1, also known as secreted apoptosis-related protein 2 (SARP-2), FRP and FrzA, is expressed in the embryonic kidney, eye, brain, teeth, salivary gland and small intestine, most often at sites of epithelial-mesenchyme interaction (5). Expression in the adult animal is strong in the eye, kidney, and heart and also prevalent in the brain and lung (2,5). sFRP-1 was first characterized as a protein that enhances the sensitivity of cells to apoptotic stimuli (3) and as an antagonist of Wnt signaling in Xenopus embryos (4). It is also characterized as a tumor suppressor in breast (6) and cervical carcinomas (7). In contrast, sFRP-1 is expressed by the majority of malignant gliomas (8) and contributes to the development of uterine leiomyomas (9), suggesting that the role of sFRP-1 is dependent on cell context. sFRP-1 has diverse activities, from inducing angiogenesis (10) in a variety of in vivo models to helping regulate Wnt-4 signaling (with sFRP-2) in renal organogenesis (11). Mouse and human sFRP-1 proteins share 94% amino acid identity (1).\n\nSource: \nA DNA sequence encoding amino acid residues Met1-Lys313 of human secreted Frizzled\nRelated Protein-1 (hsFRP-1) (Melkonyan, H.S. et al., 1997, Proc. Natl. Acad. Sci. USA 94: 13636-13641) was expressed with a C-terminal His tag in a mouse myeloma cell line, NS0.\n\nMolecular Mass: \nMature recombinant human sFRP-1 is a monomeric protein. Based on N-terminal sequencing, three peptides, Ser31, Asp41 and Phe38 at their N-termini are present in this recombinant preparation in approximately equimolar amounts. As a result of glycosylation, the recombinant preparation migrates at ~35-40kD in SDS-PAGE under reducing conditions.\n\nBiological Activity: \nMeasured by its ability to inhibit proliferation of human HeLa cervical adenicarcinoma cells. The ED50 for this effect is typically 2.5-10ug/ml.\n\nIn an alternative assay, this protein also inhibits rmWnt-3A induced activation of beta-catenin reporter TOPFLASH in HEK293T cells. \n\nStorage and Stability: \nLyophilized powder may be stored at -20 degrees C. Reconstitute to nominal volume by adding sterile PBS containing at least 0.1% HSA or BSA . Aliquot and store at -20 degrees C. Reconstituted product is stable for 6 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.

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SPECIFICATIONS

Catalog Number

S1012-86R

Size

25ug

Form

Supplied as a powder lyophilized from a solution containing PBS, pH 7.0, 50ug BSA/ug cytokine. Reconstitute with sterile PBS containing at least 0.1% HSA or BSA to prepare a stock solution of no less than 200ug/ml.

Purity

(same/more than) 95%, as determined by SDS-PAGE and visualized by silver stain. Endotoxin:(same/less than) 1 EU/ug.of the cytokine as determined by the LAL method.

References

1. Jones, S. et al., 2002, Bioessays 24:811. 2. Rattner, A. et al., 1997, Proc. Natl. Acad. Sci. USA 94:2859. 3. Melkonyan, H. et al., 1997, Proc. Natl. Acad. Sci. USA 94:13636. 4. Finch, P. et al., 1997, Proc. Natl. Acad. Sci. USA 94:6770. 5. Leimeister, C. et al., 1998, Mech. Dev. 75:29. 6. Ugolini, F. et al., 2001, Oncogene 20:5810. 7. Ko, J. et al., 2002, Exp. Cell. Res. 280:280. 8. Roth, W. et al., 2000. Oncogene 19:4210. 9. Fukuhara, K, et al., 2002, J. Clin. Endocr. Metab. 87:1729. 10. Dufourcq, P. et al., 2002, Circulation 106: 3097. 11. Yoshino, K. et al., 2001, Mech. Dev. 102:45.