Biochem/physiol Actions
Human IGFBP-3 is the major insulin-like growth factor (IGF) binding protein in plasma, where it exists in a ternary complex with IGF-I or IGF-II and the acid-labile subunit (ALS).
IGFBPs (insulin like growth factor binding proteins) regulate bioavailability of IGFs (insulin like growth factors) in cells. Binding between IGFs and IGFBPs reduces the availability of the IGFs. However, IGFBPs also concentrate IGFs in specific areas to potentiate their effects at right time. IGFBP3 binds to IGF-1. It is a tumor suppressor and is downregulated in many cancers. In serum, IGFs, IGFBP3 and the acid labile subunit (ALS) exist together as a complex. This complex is important for increasing the half life of serum IGFs.
Physical form
Lyophilized from a 0.2 μm filtered solution in 30% acetonitrile and 0.1% TFA.
Analysis Note
The biological acitivity is measured as the ability to inhibit the biological activity of 14 ng/ml recombinant human IGF-I on MCF-7 cells.
| biological source | human |
| Quality Segment | 100 |
| recombinant | expressed in NSO cells |
| assay | ≥95% (SDS-PAGE) |
| form | lyophilized powder |
| potency | 0.01-0.25 μg/mL |
| mol wt | 29 kDa |
| packaging | pkg of 25 μg |
| storage condition | avoid repeated freeze/thaw cycles |
| technique(s) | cell culture | mammalian: suitable |
| impurities | endotoxin, tested |
| UniProt accession no. | P17936 |
| storage temp. | −20°C |
| Gene Information | human ... IGFBP3(3486) |
