嗜麦芽窄食单胞菌胞内具二硫键还原活性酶蛋白的研究

Research on enzyme with disulfide reductase in Stenotrophomonas maltophilia

研究旨在克隆并表达嗜麦芽窄食单胞菌(Stenotrophomonas maltophilia)胞内具二硫键还原活性的酶蛋白。以Stenotrophomonas maltophilia基因组DNA为模板,扩增目的基因谷胱甘肽还原酶(Glr),构建重组质粒p ET-22b-Glr,并转化到表达菌株BL21(DE3)中得到重组菌,经IPTG诱导表达后,测定二硫键还原酶活性。结果表明,该重组酶基因大小为1 359 bp,酶活力为1.85 U/mg。酶学性质研究表明,重组谷胱甘肽还原酶的最适反应p H值为6.0,最适反应温度为40℃。对角蛋白酶K降解羽毛角蛋白的研究表明,该酶对其降解羽毛促进率为15%。结果揭示了Stenotrophomonas malto-philia胞内液具有促进胞外液角蛋白水解活性的内在机制。

This study was to amplify the enzyme with disulfide reductase in Stenotrophomonas mahophilia. The glutathione reductase （Glr） was amplified from Stenotrophomonas maltophilia and expressed in the BL21（DE3） with pET-22b as the vector. The recombinant plasmid was induced through adding IPTG. The length of this target gene is 1 359 bp, and the activity of the final expressed enzyme showed 1.85 U/mg. The optimum pH of the recombinant enzyme was 6.0 and the most proper reaction temperature was 40℃. Furthermore, the activity of keratinase was facilitated by this enzyme by 15% in the degradation of feather. The results indicate that there is mechanism in intracellular which is able to promote the extracellular hydrolysis of keratin in Stenotrophomonas maltophilia.