Synonyms
ADHR,HPDR2, HYPF
Description
Fibroblast growth factor 23 (FGF23) is a member of the FGF family, within a subfamily that also includes FGF19 and FGF21. FGF proteins contain a 120 amino acid (aa) core FGF domain that exhibits a betatrefoil structure. β-Klotho has been identified as co-factor required for FGF-19, 21, 23 signaling. It can obviously increase ligand-receptor affinity. Klotho has a restricted distribution that limits FGF23 activity. FGF23 is produced by osteocytes and osteoblasts in response to high circulating phosphate levels, elevated parathyroid hormone, and circulatory volume loading. It functions as an endocrine phosphatonin by suppressing circulating phosphate levels. FGF23 interaction with renal proximal tubular epithelium decreases the renal resorption of phosphate by downregulating phosphate transporters and by suppressing vitamin D production. It also decreases the intestinal absorption of phosphate.
Molecular Weight
Approximately 25.3 kDa.
AA sequence
YPNASPLLGS SWGGLIHLYT ATARNSYHLQ IHKNGHVDGA PHQTIYSALM IRSEDAGFVV ITGVMSRRYL CMDFRGNIFG SHYFDPENCR FQHQTLENGY DVYHSPQYHF LVSLGRAKRA FLPGMNPPPY SQFLSRRNEI PLIHFNTPIP RRHTRSAEDD SERDPLNVLK PRARMTPAPA SCSQELPSAE DNSPMASDPL GVVRGGRVNT HAGGTGPEGC RPFAKFI
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Purity
> 95% by SDS-PAGE and HPLC analyses.
Biological Activity
The ED50 as determined by thymidine uptake assay using FGF-receptors transfected BaF3 cells is less than 0.5 μg/mL, corresponding to a specific activity of > 2.0 × 103 IU/mg in the presence of 0.3 μg/mL of rMuKlotho and 10 μg/mL of heparin. Fully biologically active when compared to standard.
Endotoxin
< 1.0 EU per 1μg of the protein by the LAL method.
Formulation
Lyophilized from a 0.2 µm filtered concentrated solution in PBS, pH 7.4.
Reconstitution
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1% BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20°C. Further dilutions should be made in appropriate buffered solutions.