Anti-IGFBP5 (Insulin-like Growth Factor-binding Protein 5, IBP-5, IGF-binding Protein 5, IGFBP-5, IB

The insulin like growth factors (IGFs) are the major growth- promoting factors in the plasma. IGFs are secreted by a variety of cells and exert a multitude of effects on cellular survival, growth and differentiation. The A and B domains of IGFs are identical to insulin. IGF initiates their biological action through binding to the type IGF receptor (IGF-1R), a heterotrimeric protein complex with a tyrosine kinase activity. The IGF-IIR lacks the kinase activity and is actually identical to the mannose- 6-phophate receptor. Unlike most other peptide hormones, IGFs are complexed with specific binding proteins in the plasma known IGF Binding proteins (IGFBPs). At least 6 related IGFBPs (IGFBP1-6) have been well characterized. Recently, IGFBP-7/Mac25/prostacyclin- stimulating factor (PSF)/tumor adhesion factor (TAF) was originally identified as a cDNA derived from leptomeninges. These proteins are present in plasma in high concentration as compared to the membrane IGFRs. Therefore, IGFBPs have the potential to modulate the IGF action. IGFBPs have been shown to either inhibit or stimulate the IGF effects. The primary structures of mammalian IGFBPs appear to contain three distinct domains of roughly equivalent sizes: the conserved N-terminal domain, the highly variable mid region, and the conserved C-terminal domain. Human IGFBPs share approximately 36% identity. Recently several groups of cysteine-rich proteins with discrete, but striking, structural and functional similarities to the IGFBPs. This has led to the proposal of an IGFBP superfamily, comprised of the IGFBPs and these IGFBP-related proteins (IGFBP-rP1-9). Human IGFBP-5 is a 252aa mature protein that is expressed by fibroblasts, myoblasts and osteoblasts, making it the predominant IGFBP found in bone extracts. IGFBP-5 has a strong affinity for hydroxyapatite, allowing it to bind to bone cells. When bound to extracellular matrix, IGFBP-5 is protected from proteolysis and potentiates IGF activity, but when it is soluble, IGFBP-5 is cleaved to a biologically inactive 21kD fragment. , Applications:, Suitable for use in ELISA, Immunoprecipitation and Western Blot. Other applications not tested. Recommended Dilution: Western Blot: 1:1000-1:2000, ELISA: 1:10,000 (50-100ng control antigen/well)., Immunoprecipitation: 4-5ul per assay, Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.