IGFBP-3高效可溶表达、纯化及生物学活性初步研究

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

摘要:

克隆胰岛素样生长因子结合蛋白3（IGFBP-3）的cDNA片段，构建原核表达载体pET-DsBA-IGFBP3。将该重组质粒转化大肠杆菌BL21 (DE3)plysS中，诱导表达IGFBP-3融合蛋白（简称D-IGFBP3）。经检测融合蛋白主要以可溶形式表达。表达产物用His亲和层析柱纯化，获得了纯度超过95%的重组IGFBP-3融合蛋白。Western-blot 结果表明在相应分子量处有一条特异性条带。细胞活性研究显示它对MCF-7细胞生长具有一定的抑制作用，且在体外具有与IGF-I结合的活性。

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.