Recombinant Human Complement Factor H-related 4/CFHR4, CF

2 μg/lane of Recombinant Human Complement Factor H‑related 4 was resolved with SDS-PAGE underreducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Bluestaining, showing bands at ~42 kDa and ~40 kDa, respectively.

When Recombinant Mouse Complement Component C3d (Catalog # 2655-C3) is immobilized at 2 µg/mL, 100 µL/well, Recombinant HumanComplement Factor H-related 4/CFHR4 (Catalog # 5980‑CH) binds with an ED50 of1‑6 ng/mL.

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

Recombinant Human Complement Factor H-related 4/CFHR4, CF Summary

• Additional Information: His-tag
• Details of Functionality: Measured by its binding ability in a functional ELISA. When Recombinant Mouse Complement Component C3d (Catalog # 2655-C3) is immobilized at 2 µg/mL (100 µL/well), Recombinant Human Complement Factor H‑related 4/CFHR4 binds with an ED₅₀ of 1-6 ng/mL.
• Source: Spodoptera frugiperda, Sf 21 (baculovirus)-derived human Complement Factor H-related 4/CFHR4 protein
  Gln19-Glu331, with a C-terminal 10-His tag
• Accession #: CAA66980
• N-terminal Sequence: No results obtained. Gln19 inferred from enzymatic pyroglutamate treatment revealing Glu20.
• Protein/Peptide Type: Recombinant Enzymes
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Theoretical MW: 37 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: 39-45 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 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in Tris and NaCl with Trehalose.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 500 μg/mL in water.

Notes

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

Alternate Names for Recombinant Human Complement Factor H-related 4/CFHR4, CF

• complement factor H-related protein 4
• CFHL4
• CFHR4
• Complement Factor Hrelated 4
• Complement Factor H-related 4
• FHR4
• FHR-4

Background

Complement factor H-related protein 4 (CFHR4) is a secreted glycoprotein member of the factor H family of glycoproteins (1). The human complement factor H protein family consists of the complement and immune regulators factor H, the factor H-like protein 1 (FHL-1) and five factor H-related proteins (FHR-1 to -5) (1). The genes of this family are located on human chromosome 1q32, which is known as the regulator of complement activation (RCA) gene clusters (2). CFHRs are exclusively composed of individually folded protein domains, termed short consensus repeats (SCRs) or complement control modules. All CFHRs, including CFHR4, are capable of binding complement factor C3b, discriminate between self and non-self cell surfaces, and have been proposed to deregulate complement activation by inhibiting interaction of CFH with C3b and C3d (1, 3). CFHR4 activates complement through its interaction with C3b (4). CFHR4 can also bind to native (pentameric) C-reactive protein (pCRP) through its first SCR domain and is suggested to promote pCRP binding to necrotic cells surfaces, thus promoting cell clearance (5). CFHR4 is synthesized as 2 isoforms by hepatocytes and circulates in plasma. The longer 86 kDa alternative splice form termed FHR4A includes a duplication insertion of 247 aa. The CFHR4 product represents the shorter isoform, FHR4B, containing 5 of 9 SCRs (6).

1. Skerka, C. et al. (2013) Mol. Immunol. 56:170.
2. Diaz-Guillen, M.A. et al. (1999) Immunogenetics 49:549.
3. Hellwage, J. et al. (1999) FEBS Lett. 462:345.
4. Hebecker, M. and J. Jozsi (2011) J. Biol. Chem. 287:19528.
5. Mihlan, M. et al. (2009) Mol. Immunol. 46:335.
6. Jozsi, M. et al. (2005) Eur. J. Hum. Genet. 13:321.

Bioinformatics

• Uniprot:
  • CAA66980 ()