1. Measured by its ability to bind human IGF1 in functional ELISA. 2. Measured by its ability to bind human IGF2 in functional ELISA. 3. Measured by its ability to inhibit the biological activity of IGFI or IGFII on MCF7 human breast adenocarcinoma cells (Karey, K.P. et al. (1988) Cancer Research 48:4083.). The ED50 for this effect is typically 0.04-0.4 μg/mL in the presence of 14 ng/mL human IGFII.

IGFBP-4 Protein, Human, Recombinant (His) is expressed in HEK293 mammalian cells with His tag. The predicted molecular weight is 27.4 kDa and the accession number is A0A024R1U8.

Human

HEK293 Cells

HT29-IGFBP,IBP4,BP-4,IGFBP-4,insulin-like growth factor binding protein 4

Human IGFBP4 (NP_001543.2) precursor (Met 1-Glu 258) with a C-terminal polyhistidine tag

> 95 % as determined by SDS-PAGE

A Certificate of Analysis (CoA) containing reconstitution instructions is included with the products. Please refer to the CoA for detailed information.

It is recommended to store recombinant proteins at -20°C to -80°C for future use. Lyophilized powders can be stably stored for over 12 months, while liquid products can be stored for 6-12 months at -80°C. For reconstituted protein solutions, the solution can be stored at -20°C to -80°C for at least 3 months. Please avoid multiple freeze-thaw cycles and store products in aliquots.

Insulin-like growth factor-binding protein 4 (IGFBP-4) is a 24-kDa protein that binds insulin-like growth factor 1 (IGF-1) and IGF-2 with high affinity and inhibits IGF action in vitro. The Insulin-like growth factor-binding protein also known as IGFBP serves as a carrier protein for Insulin-like growth factor 1. IGFBPs are distinct but are sharing regions with strong homology. All members of the IGFBP family bind IGF-I and IGF-II with about equal affinity. Insulin-like growth factor (IGF) binding proteins (IGFBPs) have been shown to either inhibit or enhance the action of IGF or act in an IGF-independent manner in the prostate. IGF-binding protein-4 (IGFBP-4) inhibits IGF-I action in vitro and is the most abundant IGFBP in the rodent arterial wall. Expression of IGFBP-4 mRNA in nontransgenic littermates was maximal in the liver and kidney. IGFBP-4 is a functional antagonist of IGF-I action on SMC. There is mounting evidence that the structure of the IGFBP proteins plays a key role in the regulation of IGF bioavailability, by modulating its molecular size, capillary membrane permeability, target tissue specificity, cell membrane adherence, and IGF affinity.