抑瘤素-M(OSM)在GST融合表达系统中的表达、纯化和活性测定

抑瘤素Ｍ是一种具有多种生物活性的细胞因子，具有重要的研究价值和潜在的应用前景。基于ＧＳＴ融合表达载体，构建了一个ＯＳＭ的高效表达系统，诱导表达后融合蛋白占全菌蛋白的５０％以上，在低温诱导的条件下，可溶性蛋白中融合蛋白的含量可达１５％。在对包涵体形式的融合蛋白变复性的基础上，通过亲和层析一步纯化达到９０％左右的纯度。对融合蛋白进行了活性测定，结果提示了Ｎ端的头两个氨基酸对ＯＳＭ的生物活性是重要的。

EXPRESSION, PURIFICATION AND BIO ACTIVITY ANALYSIS OF ONCOSTATIN IN GST FUSION EXPRESSION SYSTEM

Oncostatin (OSM) is an important cytokine which has diverse biological activities. It may be useful in basic scientific and clinical studies. OSM was efficiently expressed by cloning the OSM gene into GST fusion expression vector. The level of expression of the fusion protein was about 50% of the total cell protein by SDS PAGE analysis. The percentage of fusion protein in soluble protein could be 15% when the induction was in low temperature. The purity of purified GST OSM with an affinity chromatography column was about 90% after the inclusion bodies had denatured and renatured. The result of activity study showed that the first two amino acids in N terminal of the OSM were important to the biological activity of OSM.