重组人成骨蛋白-1的离子交换及分子排阻色谱法纯化及其复性研究

经发酵大量表达重组人成骨蛋白-1(rhOP-1)。SDS-PAGE发现rhOP-1表达量占细菌总蛋白的35%。菌体经裂解、洗涤后,用8mol/L尿素溶解包涵体,离心后提取目的蛋白。经离子交换色谱法对变性状态下的目的蛋白进行纯化,绝大部分杂蛋白被去除,目的蛋白纯度达93%以上。为进一步提高目的蛋白浓度,采用分子排阻色谱法对目的蛋白进行再次纯化,纯度达98%以上。利用降低尿素梯度的方法对纯化的蛋白进行复性,二聚体的含量在50%以上。Westernblot证明了复性后的目的蛋白以单体和有活性的二聚体的形式存在。

Purification and Refolding of Recombinant Human Osteogenic Protein-1 by Ion-exchange Chromatography and Molecular Exclusion Chromatography

Recombinant human Osteogenic Protein-1(rhOP-1) was generously expressed in fermentation. The SDS-PAGE showed that the amount of rhOP-1 expression were 35% in total bacterial proteins. It was washed and collected after the sonication. 8 mol/L urea was used to dissolve the inclusion body. Most of the impurity were eliminated through the SP-Sepharose ion-exchange chromatography, and the purity rate of target protein exceeded 93%. After Sephacryl S-100 molecular exclusion chromatography, rhOP-1 was purified to homogeneity. The purified rhOP-1 was refolded in lower urea gradiently method, and the content of dimer was more than 50%. Western blot showed that the refolding protein was in the forms of monomer or activated dimer.