Recombinant Human IGFBP4

The lyophilized protein is stable for a few weeks at room temperature, but best stored at -20C. Reconstituted human BD-4 should be stored in working aliquots at -20C. Avoid repeated freeze-thaw cycles.

IGFBPs control the distribution, function and activity of IGFs in various cell tissues and body fluids. IGFBP4 is the major IGFBP produced by osteoblasts, and is also found in the epidermis, ovarian follicles, and other tissues. IGFBP4 inhibits the activity of IGF-I and IGF-II by binding in a manner that results in the formation of complexes with reduced ability to signal through cell surface IGF receptors. IGFBP4 can inhibit the growth of chick pelvis cartilage and HT29 colon adenocarcinoma cells by blocking the mitogenic actions of IGFs, and has also been shown to reduce colony formation by colorectal cancer cells via an IGF independent pathway. The biological effects of IGFBP4 can be regulated by Pregnancy Associated Plasma Protein A (PAPP-A), which reduces IGFBP4/ IGF binding affinity by proteolytically cleaving IGFBP4. The modulation of IGFBP4 activity by PAPP-A is an important component in the regulation of ovarian folliculogenesis and in the growth inhibition of responding ovarian cancer cells. Recombinant human IGFBP4 is a 26.1 kDa protein consisting of 238 amino acid residues including the IGFBP domain and thyroglobulin type-I domain.

Centrifuge vial prior to opening . Reconstituted in water to a concentration of 0.1-1.0 mg/ml. This solution can be diluted in water or other buffer solutions or stored at -20C.