Description : |
IGFBP-4 (insulin-like growth factor binding protein 4) is member of the IGFBP family of structurally similar secreted glycoproteins that maintain IGF-I and IGF-II in the circulation and direct them to their target tissues. IGF-binding proteins prolong the half-life of the IGFs and have been shown to either inhibit or stimulate the growth promoting effects of the IGFs on cell culture. They alter the interaction of IGFs with their cell surface receptors. IGFBP-4 consistently inhibits several cancer cells in vivo and in vitro. |
Source : |
Insect Cell |
Species : |
Human |
Form : |
Lyophilized from a 0.2μm filtered concentrated solution in 20mM Tris-HCl, pH 8.0, 150mM NaCl. |
Bio-activity : |
Fully biologically active when compared to standard. The ED50 as determined by its ability to inhibit IGF-II induced proliferation of MCF-7 cells is less than 0.1 μg/ml, corresponding to a specific activity of > 1.0 × 10⁴ IU/mg in the presence of 14 ng/ml of rHuIGF-II. |
Molecular Mass : |
The apparent molecular weight is about 30 kDa in SDS-PAGE under reducing conditions, containing 237 amino acids. |
Protein length : |
237 |
AA Sequence : |
DEAIHCPPCSEEKLARCRPPVGCEE LVREPGCGCCATCALGLGMPCGVYT PRCGSGLRCYPPRGVEKPLHTLMHG QGVCMELAEIEAIQESLQPSDKDEG DHPNNSFSPCSAHDRRCLQKHFAKI RDRSTSGGKMKVNGAPREDARPVPQ GSCQSELHRALERLAASQSRTHEDL YIIPIPNCDRNGNFHPKQCHPALDG QRGKCWCVDRKTGVKLPGGLEPKGE LDCHQLADSFRE |
Endotoxin : |
Less than 0.1 EU/μg of rHuIGF-BP4, Insect Cell as determined by LAL method. |
Purity : |
>97% by SDS-PAGE and HPLC analysis. |
Storage : |
Use a manual defrost freezer and avoid repeated freeze-thaw cycles. 12 months from date of receipt, -20 to -70 centigrade as supplied. 1 month, 2 to 8 centigrade under sterile conditions after reconstitution. 3 months, -20 to -70 centigrade under sterile conditions after reconstitution. |
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 centigrade. Further dilutions should be made in appropriate buffered solutions. |