溶藻弧菌asp基因在大肠杆菌中表达活性研究及条件优化

为进一步研究溶藻弧菌碱性丝氨酸蛋白酶(ASP)蛋白生物学活性和功能,将构建的pET23d-asp在大肠杆菌BL21(DE3)中表达,对表达产物进行纯化分析,并优化表达条件。结果表明:在咪唑洗脱缓冲液浓度为100 mmol/L时,表达的可溶性ASP被大量洗脱,纯化的ASP相对分子质量约为42 000,具有蛋白活性;在诱导温度28℃、异丙基-β-D硫代半乳糖苷(Isopropyl-β-D-thiogalactopyranoside,IPTG)浓度1 mmol/L及诱导时间16 h时,表达的活性ASP蛋白最多。

Optimization of Expression Conditions and Activity of asp Gene from Vibrio alginolyticus in Escherichia coli

In order to further the study of the biological activity and function of ASP from Vibrio alginolyticus,the recombinant plasmid pET23d-asp were transformed into the host E.coli BL21(DE3).The expressed product was purified and analyzed,and the expression conditions were optimized.The soluble ASP was purified when the chromatogram column was eluted by 100 mmol/L imidazole eluting buffer.The purified ASP had enzymatic activity and its relative molecular weight was 42 000.When the expression was induced with 1 mmol/L Isopropyl-β-D-thiogalactopyranoside(IPTG) for 16 h at 28 ℃,the maximum amounts of soluble proteins were obtained.