Technical Data
Insulin-Like Growth Factor Binding Protein 5, Recombinant, Human (IGFBP5, IBP5, IBP-5)
Molecular Biology Storage: -20CShipping: Blue Ice
Insulin-like growth factor binding protein 5 (IGFBP5) is one of a family of proteins that bind IGF and modulate its biological activity. IGFBP-5 is the predominant IGFBP found in bone extracts. The superfamily of insulin-like growth factor (IGF) binding proteins include the six high-affinity IGF binding proteins (IGFBP) and several low-affinity binding proteins referred to as IGFBP related proteins (IGFBP-rP). All IGFBP superfamily members are cysteine-rich proteins with conserved cysteine residues, which are clustered in the amino- and carboxy-terminal thirds of the molecule. IGFBPs modulate the biological activities of IGF proteins. Some IGFBPs may also have intrinsic bioactivity that is independent of their ability to bind IGF proteins. Post-translational modifications of IGFBP, including glycosylation, phosphorylation and proteolysis, have been shown to modify the affinities of the binding proteins to IGF. IGFBP5 is the most conserved and is developmentally up-regulated in key lineages and pathologies; in vitro studies suggest that IGFBP-5 functions independently of IGF interaction. Genetic ablation of individual IGFBP's has yielded limited phenotypes because of substantial compensation by remaining family members.

Recombinant Human IGFBP-5 produced in E. coli is a single, non-glycosylated, polypeptide chain containing 253 amino acids and having a molecular mass of 28613 Dalton. IGFBP-5 is purified by proprietary chromatographic techniques.

Amino Acid Sequence:
The sequence of the first five N-terminal amino acids was determined and was found to be Met-Leu-Gly-Ser-Phe.

Biological Activity:
IGFBP-5 is fully biologically active when compared to standards. The ED50, calculated by its ability to inhibit IGF-II induced proliferation of MCF-7 is <0.3g/ml in the presence of 15ng/ml of Human IGF-II.

Storage and Stability:
Lyophilized powder may be stored at -20C. Reconstitute with sterile ddH2O, 0.1% HSA or BSA. Aliquot and store at -20C. Reconstituted product is stable for 6 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

Molecular Weight:
Source: E. coli
Purity: Chromatographically purified 98% by RP-HPLC, FPLC, or reducing/non-reducing SDS-PAGE Silver Stain.
Concentration: ~1mg/ml
Form: Supplied as a lyophilized powder from 10mM sodium citrate, pH 3.0. Reconstitute with sterile ddH2O to 100ug/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. Prolactin inhibits cell loss and decreases matrix metalloproteinase expression in the involuting mouse mammary gland but fails to prevent cell loss in the mammary glands of mice expressing IGFBP-5 as a mammary transgene. J Mol Endocrinol 2006 Jun;36(3):435-48 2. Growth hormone suppresses the expression of IGFBP-5, and promotes the IGF-I-induced phosphorylation of Akt in bovine mammary epithelial cells. Domest Anim Endocrinol 2006 Apr 18; 3. Mannan-binding lectin-associated serine protease 3 cleaves synthetic peptides and insulin-like growth factor-binding protein 5. Arch Biochem Biophys 2006 May 15;449(1-2):164-70 4. Insulin-like growth factor-binding protein-5 (IGFBP-5): a critical member of the IGF axis. Biochem J 2006 Apr 1;395(1):1-19 5. Insulin-like growth factor-binding protein-5 activates plasminogen by interaction with tissue plasminogen activator, independently of its ability to bind to plasminogen activator inhibitor-1, insulin-like growth factor-I, or heparin. J Biol Chem 2006 Apr 21;281(16):10883-9 6. Insulin-like growth factor binding protein (IGFBP)-5 is upregulated during both differentiation and apoptosis in primary cultures of mouse mammary epithelial cells. J Cell Physiol 2006 May;207(2):471-9

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