|Datasheet||Specific References||Reviews||Related Products||Protocols|
|Human Cell lysate that Human IGFBP3 / IBP3 transfected / overexpressed for Western blot (WB) positive control. The whole cell lysate is provided in 1X Sample Buffer (1X modified RIPA buffer+1X SDS loading buffer).|
|A DNA sequence encoding the mature form of human IGFBP3 (NP_000589.2) (Gly28-Lys 291) was fused with a polyhistidine tag at the N-terminus.|
|The secreted recombinant human IGFBP3 comprises 280 amino acids with a predicted molecular mass of 31 kDa. As a result of glycosylation, the apparent molecular mass of rhIGFBP3 is approximately 40-45 kDa in SDS-PAGE under reducing conditions.|
|Cell lysate was prepared by homogenization in ice-cold modified RIPA Lysis Buffer with cocktail of protease inhibitors (Sigma). Cell debris was removed by centrifugation. Protein concentration was determined by Bradford assay (Bio-Rad protein assay, Microplate Standard assay). The cell lysate was boiled for 5 min in 1 x SDS loading buffer (50 mM Tris-HCl pH 6.8, 12.5% glycerol, 1% sodium dodecylsulfate, 0.01% bromophenol blue) containing 5% b-mercaptoethanol, and lyophilized.|
|Modified RIPA Lysis Buffer: 50 mM Tris-HCl pH 7.4, 150 mM NaCl, 1mM EDTA, 1% Triton X-100, 0.1% SDS, 1% Sodium deoxycholate, 1mM PMSF.|
|12.5% SDS-PAGE Stained with Coomassie Blue after protein purification.|
|Samples are stable for up to twelve months from date of receipt.|
|1. Centrifuge the tube for a few seconds and ensure the pellet at the bottom of the tube. 2. Re-dissolve the pellet using 200μL pure water and boil for 2-5 min. 3. Store the lyophilized cell lysate at 4℃. After re-dissolution, recommend to aliquot it into smaller quantities and store at -80℃.|
|1 X Sample Buffer (1 X modified RIPA buffer+1 X SDS loading buffer).|
|Store at 4℃. After re-dissolution, aliquot and store at -80℃.|
|Western blot (WB): Use at an assay dependent dilution.|
Other Applications: Not tested.
Optimal dilutions/concentrations should be determined by the end user.
The Insulin-like Growth Factor (IGF) signaling system plays a central role in cellular growth, differentiation and proliferation. IGFBP3 is the most abundant IGF binding protein in human serum and has been shown to be a growth inhibitory, apoptosis-inducing molecule, capable of acting via IGF-dependent and IGF-independent mechanisms. It appears to function both by cell cycle blockade and the induction of apoptosis. IGFBP3 can be transported to the nucleus by an importin beta mediated mechanism, where it has been shown to interact with the retinoid X receptor alpha and possibly other nuclear elements. IGFBP3 antiproliferative signalling appears to require an active transforming growth factor beta (TGF-beta) signalling pathway, and IGFBP3 stimulates phosphorylation of the TGF-beta signalling intermediates Smad2 and Smad3. IGFBP3 has IGF-independent roles in inhibiting cell proliferation in cancer cell lines. Nuclear transcription factor, retinoid X receptor (RXR)-alpha, and IGFBP3 functionally interact to reduce prostate tumor growth and prostate-specific antigen in vivo. Several clinical studies have proposed that individuals with IGFBP3 levels in the upper range of normal may have a decreased risk for certain common cancers. This includes evidence of a protective effect against breast cancer, prostate cancer, colorectal cancer, and lung cancer. Moreover, IGFBP3 inhibits insulin-stimulated glucose uptake into adipocytes independent of IGF.