Synonyms
Growth-hormone-dependant Binding Protein, IBP-3, IGF-binding protein 3
Description
IGF-BP3 is a 30 kDa, cysteine-rich secreted protein. It is the major IGF binding protein present in the plasma of human and animals, and it is also found in α-granules of platelets. In addition to its ability to modulate the activity of IGF-I and IGF-II, IGF-BP3 exerts inhibitory effects on follicle stimulating hormone (FSH) activity. Decreased plasma levels of IGF-BP3 often results in dwarfism, whereas elevated levels of IGF-BP3 may lead to acromegaly. The expression of IGF-BP3 in fibroblasts is stimulated by mitogenic growth factors, such as Bombesin, Vasopressin, PDGF, and EGF. Recombinant Human IGF-BP3 is a 28.8 kDa protein consisting of 264 amino acid residues.
Molecular Weight
Approximately 28.8 kDa.
AA sequence
GASSAGLGPV VRCEPCDARA LAQCAPPPAV CAELVREPGC GCCLTCALSE GQPCGIYTER CGSGLRCQPS PDEARPLQAL LDGRGLCVNA SAVSRLRAYL LPAPPAPGNA SESEEDRSAG SVESPSVSST HRVSDPKFHP LHSKIIIIKK GHAKDSQRYK VDYESQSTDT QNFSSESKRE TEYGPCRREM EDTLNHLKFL NVLSPRGVHI PNCDKKGFYK KKQCRPSKGR KRGFCWCVDK YGQPLPGYTT KGKEDVHCYS MQSK
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Purity
> 98 % by SDS-PAGE and HPLC analyses.
Biological Activity
Fully biologically active when compared to standard. The ED50 as determined by inhibiting IGF-II induced proliferation of serum free human MCF-7 cells is less than 200 ng/mL, corresponding to a specific activity of > 5.0 × 103 IU/mg in the presence of 15 ng/ml of rHuIGF-II.
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.