Flt3-L

Recombinant Human Flt3-Ligand produced in E.coli is a soluble 17.6 kDa polypeptide containing 155 amino acid residues, which comprises the extracellular domain of the transmembrane flt3-ligand protein.

Flt-3 ligand (FL) is a recently identified hematopoietic cytokine whose activities are mediated by binding to the transmembrane glycoprotein Flt-3. Flt-3 was first discovered as a member of the class III subfamily of receptor tyrosine kinases (RTK) whose expression among hematopoietic cells was found to be restricted to highly enriched stem/progenitor cell populations. Additional class III RTKs include the receptors from SCF, M-CSF and PDGF. Not surprisingly, Flt-3 ligand is also structurally related to M-CSF and SCF. All three cytokines have been shown to exist both as type I transmembrane proteins and as soluble proteins. The predominant human FL isoform is a transmembrane protein that can undergo proteolytic cleavage to generate a soluble form of the protein. An alternatively-spliced FL mRNA, encoding a soluble form of the human FL, has also been identified. FL is widely expressed in various human and mouse tissues. At the amino acid sequence level, human and mouse FL are approximately 72% identical and the two proteins exhibit cross-species activity. FL has been shown to synergize with a wide variety of hematopoietic cytokines to stimulate the growth and differentiation of early hematopoietic progenitors.

Sterile filtered lyophilized powder, with 20mM Tris-HCl, 20mM NaCl, pH7.4.

rHuFlt3-L is fully biologically active when compared to standards. Its specific activity is ≥1×10⁶IU/mg.

Less than 10 IEU/mg of rHuFlt3-L determined by LAL test.

It is recommended to reconstitute the lyophilized rHuFlt3-L in sterile 18MΩ-cm H₂O not less than 100ug/ml, which can then be further diluted to other aqueous solutions.

Lyophilized rHuFlt3-L although stable at room temperature for 3 weeks, should be stored desiccated below -18^°C. Upon reconstitution rHuFlt3-L should be stored at 4^°C between 2-7 days and for future use below -18^°C. Aliquot to avoid repeated freeze-thaw cycles.

FL, Fms-related tyrosine kinase 3 ligand, FLK2, STK1, CD135, Stem Cell Tyrosine Kinase 1, FLT3LG, Flt3, Flt3 ligand, Flt3L; SL cytokine precursor

Cytokine-cytokine receptor interaction; Hematopoietic cell lineage

cytokine activity