IGF-BPs controls the distribution, function and activity of IGFs in various cell tissues and body fluids. Currently, there are seven named IGF-BPs that form high-affinity complexes with both IGF-I and IGF-II. IGF-BP1 is a 25.4 kDa, cysteine-rich, secreted protein expressed in the liver, deciduas, kidneys, and in amniotic fluid, where it is the most abundant IGF-BP. Levels of IGF-BP1 in serum are lowest after food consumption. IGF-BP1 binds to both IGF-I and IGF-II with equal affinity. Phosphorylated IGF-BP1 hinders IGF actions, whereas nonphosphorylated IGF-BP1 is stimulatory. Recombinant Human IGF-BP1 is a 25.4 kDa protein consisting of 235 amino acid residues (Isoform A).
Amino Acid Sequence
The ED 50 was determined by its ability to inhibit IGF-I induced proliferation of MCF-7 is 0.5 µg/ml in the presence of 6 ng/ml of human IGF-I.
Endotoxin level is <0.1 ng/μg of protein (<1EU/μg).
Centrifuge the vial prior to opening. Reconstitute in water to a concentration of 0.1–1.0 mg/ml. Do not vortex. For extended storage, it is recommended to further dilute in a buffer containing a carrier protein (example 0.1% BSA) and store in working aliquots at-20°C to –80°C.