鲨肝刺激物质类似物基因在大肠杆菌中的表达与产物活性分析

Expressing and bioactivity analysis of shark hepatic stimulate substance analogue in Escherichia coli

构建了鲨肝刺激物质类似物基因片段的原核表达载体质粒 (pET-sHSS) ,转化大肠杆菌后通过IPTG诱导获得原核表达产物 ,并利用凝胶层析方法对表达产物进行了分离纯化 ;进一步利用MTT比色法研究了该重组产物对肝癌细胞株SMMC -7721的增殖影响。结果表明 ,在1mmol/L的IPTG的诱导下 ,鲨肝刺激物质类似物基因片段在大肠杆菌BL21菌株中获得表达 ,表达产物的相对分子质量大小约为17500u,占菌体可溶性蛋白总量的38%左右 ;纯化后的产物在低浓度下 (<50ng/L)具有明显刺激SMMC7721细胞株增殖的活性 ,高浓度下 (>100ng/L)则明显抑制该肿瘤细胞株的生长 。

After being induced with1mmol/LIPTG,the recombinational protein was purified by Gel chromotograˉbing and the activity analyzed with MTT,the prokargotic expression plasmid of sharks hepatic stimulant analogues gene was constructed and transformed into Escherichia coli BLZL line. The results showthat the quantities of recombinant protein to the about38%of the total soluble proteins of BL21under the induction of IPTG,its molecular weight is about17500u analyzed by SDS-PAGE electrophoresis.The purified products can improve the proliferation of SMMC7721cell under the concentration of50ng/L,but will inhibit the cell's proliferation up to100ng/L.Therefore,the recombinant product of shark hepatic stimulant substance analogue gene has the similar activities as the natural form purified from shark lives before.