Soluble High-expression，Purification and Bioassay of IGFBP-3

Abstract:

cDNA for Insulin-like growth factor binding protein 3 was cloned and constructed a prokaryotic expression vector——pET-DsBA-IGFBP3. The construct was transformed into E.coli BL21(DE3)plysS. The induced fusion protein(D-IGFBP3) was expressed successfully in soluble form. We obtained D-IGFBP3 the purify of which is over 95% after purification by His affinity chromatography. The product was identified by Western-blot. The cell assay showed that the obtained fusion protein can inhibit the growth of MCF-7 and bind with IGF-I in vitro.