Unlike insulin, both IGF-I and IGF-II circulate in plasma tightly bound to specific binding proteins. Two major forms of IGFbinding proteins have been identified in human plasma, a low molecular weight form and a high molecular weight form. The low molecular weight IGF-binding protein (IGFBP1) is synthesized in liver, secretory endometrium, and decidua. It binds both IGF I and IGF II with high affinity. Insulin-like growth factor binding protein-1 IGFBP-1 ~30-kD, also known as IBP1 or placental protein 12, or IGF-BP25, chromosome 7p14-p12)) is a member of the superfamily of insulin-like growth factor (IGF) binding proteins which include six high-affinity IGF binding proteins (IGFBP1-6) and at least four low-affinity binding proteins referred to as IGFBP related proteins (IGFBP-rP). The IGFBP members are cysteinerich proteins with conserved cysteine residues, clustered in the amino-terminal and the carboxy-terminal regions of the molecule. Contained within IGFBP-1 and -2 is an integrin receptor recognition sequence (RGD) that is responsible for promoting cell migration by an IGF-independent action. IGFBPs hold a central position in IGF ligand-receptor interactions through influences on both the bioavailability and distribution of IGFs in the extracellular environment. IGFBPs will either inhibit or enhance the biological activities of IGF or act in an IGF-independent manner. Source: Human IGFBP-1 (218aa), expressed in NSO cells. Applications: Suitable for use in Western Blot. It is not suitable for ELISA or other applications where native protein is required. Other applications not tested. Recommended Dilution: Western Blot: 10 ul/lane. SDS may crystallize in cold conditions. It should redissolve by warming before taking it from the stock. It should be heated once prior to loading on gels. Optimal dilutions to be determined by the researcher. Storage and Stability: Lyophilized powder may be stored at -20C. Stable for 12 months at -20C. Reconstitute with sterile buffer or ddH2O. Aliquot to avoid repeated freezing and thawing. 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.
