Technical Data
Fibroblast Growth Factor 19, Recombinant, Human (FGF19)
Molecular Biology Storage: -20CShipping: RT
Human FGF-19 Fibroblast growth factor 19 (FGF-19) belongs to the large FGF family which has at least 23 members.1, 2 All FGF family members are heparin-binding growth factors with a core 120 amino acid (aa) FGF domain that allows for a common tertiary structure. FGFs are expressed during embryonic development and in restricted adult tissues. They act on cells of mesodermal and neuroectodermal origin to regulate diverse physiologic functions including angiogenesis, cell growth, pattern formation, embryonic development, metabolic regulation, cell migration, neurotrophic effects and tissue repair.3, 4 Signaling receptors for FGFs are type I
transmembrane receptor tyrosine kinases belonging to the Ig superfamily. Four distinct but related classes of FGF receptors, FGF R1, 2, 3, and 4, exist. Through alternative splicing, multiple isoforms for FGF R1, 2 and 3, with distinct ligand recognition profiles, are also generated.4
Human FGF-19 cDNA predicts a 251 aa precursor protein with a 22 aa signal peptide and a 229 aa secreted mature protein with no potential N-linked glycosylation sites.1, 2 Among FGF family members, human FGF-19 is most closely related chicken FGF-19 and murine FGF-15, sharing approximately 61% and 51% aa sequence identity, respectively.1, 2, 5 Neither the human orthologue of mouse FGF-15, nor the mouse counterpart of human FGF-19 has been identified. With the exception of adult gall bladder epithelium, FGF-19 expression is restricted to fetal tissues.1, 2 Unlike most FGFs which bind to and activate more than one FGF receptor, FGF-19 is a specific ligand for FGF R4.2 Similarly, another FGF family member, FGF-7 (KGF), only activates KGF R, the IIIb isoform of FGF R2.4 During chick embryogenesis, FGF-19 has been shown to act synergistically with Wnt-8c to initiate inner ear development.5

Source: A DNA sequence encoding the mature human FGF-19 (Phe 27-Lys 216, Accession O95750) (Xie, M. et al., 1999, Cytokine 11:729-735)

Molecular Mass: Based on N-terminal sequencing, the recombinant mature human FGF-19 has Phe 27 at the amino terminus and has a calculated molecular mass of 21kD.

Biological Activity:
FGF-19 is a high affinity heparin dependent ligand for FGFR4. Embryonic regions known to express FGF-19 include skin, cartilage, retina, gall bladder and small intestine. Activity measured by its ability to bind rhFGF R4/Fc in a functional ELISA. Immobilized rhFGF R4/Fc at 5ug/ml (100ul/well) can bind rhFGF-19 with a linear range of 3-200ng/ml.

Storage and Stability:
Lyophilized samples are stable for up to six months at -20C to -70C. Upon reconstitution, this cytokine can be stored under sterile conditions at 2-8 C for one month or at -20C to -70C in a manual defrost freezer for three months without detectable loss of activity. Avoid repeated freeze-thaw cycles.
Source: E. coli
Purity: 97% by SDS PAGE and HPLC analyses. Purified by sequential chromatography. Endotoxin: 0.1ng/ug
Form: Supplied as a lyophilized powder from a 0.2um filtered solution in PBS containing 50ug of bovine serum albumin per 1ug of cytokine. Reconstitute with sterile, ddH2O, 0.1-1% BSA to 0.1-1mg/ml.

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
1. Nishimura, T. et al., 1999, Biocheim. Biophys. Acta 1444:148.
2. Xie, M. et al., 1999, Cytokine 11:729.
3. Goldfarb, M., 1996, Cytokine & Growth Factor Reviews 7:311.
4. Green, P. et al., 1996, BioEssays 18:639.
5. Ladher, R.K. et al., 2000, Science 290:1965.

Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.