Recombinant Human Follistatin-like 4 Protein, CF

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human Follistatin-like 4 Protein, CF Summary

• Details of Functionality: Measured by its ability to inhibit BMP-6-induced alkaline phosphatase production by MC3T3‑E1 mouse preosteoblast cells. The ED₅₀ for this effect is 2-10 µg/mL in the presence of 0.1 µg/mL of recombinant human BMP-6.
• Source: Chinese Hamster Ovary cell line, CHO-derived human Follistatin-like 4/FSTL4 protein
  Trp23-Val842, with an N-terminal 7-His tag and Asn
• Accession #: NP_055897
• N-terminal Sequence: His
• Protein/Peptide Type: Recombinant Proteins
• Gene: FSTL4
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Endotoxin Note: <0.01 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 93.6 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 100 kDa, reducing conditions

Packaging, Storage & Formulations

• 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.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS.
• Purity: >95%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Reconstitution Instructions: Reconstitute at 300 μg/mL in sterile PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human Follistatin-like 4 Protein, CF

• Follistatin like 4
• Follistatin-like 4
• Follistatin-like protein 4
• follistatin-related protein 4
• FSL4
• FSTL4
• KIAA1061

Background

Follistatin-like 4 (FSTL4) is a presumably secreted member of the follistatin domain-containing protein family (1). Follistatin itself is a potent inhibitor of the TGF-beta superfamily member, activin (1, 2), and this activity is reflected in several other proteins of this family that contain varying numbers of the cysteine-rich follistatin domain. Many of these are matrix proteins such as SPARC and testican for which TGF-beta superfamily inhibition status is presumed but unknown (2, 3). R&D Systems recombinant human FSTL4 inhibits the ability of a TGF-beta superfamily member, BMP-6, to induce osteoblast differentiation of a mouse fibroblast cell line. Human FSTL4 cDNA encodes an 842 amino acid (aa) protein containing a 22 aa signal sequence, a follistatin (EGF- and kazal-like) domain, an EF‑hand calcium-binding motif, and two Ig-like cell adhesion molecule-type (IgCAM) domains (1, 4). The second IgCAM domain contains a consensus sequence for FGF/FGF receptor interaction (4). Mature human FSTL4 shares 84%, 82% and 82% aa identity with mouse, rat and bovine FSTL4, respectively. Identity with other follistatin-like family members is mainly within consensus residues of the follistatin domain. Of two reported human FSTL4 isoforms, one is missing the follistatin and EF‑hand domains, while the other contains all recognized domains, but is truncated after aa 600 (4).

1. Glusman, G. et al. (2004) BMC Evol. Biol. 4:43.
2. Schneyer, A. et al. (2001) Mol. Cell. Endocrinol. 180:33.
3. Hohenester, E. et al. (1997) EMBO J. 16:3778.
4. Swissprot Accession # Q6MZW2.

Bioinformatics

• Gene Symbol: FSTL4
• Uniprot:
  • NP_055897(Human)