摘要：The syntheses and preliminary biological evaluation of a potentially bioreductive A-mustard and paclitaxel conjugate prodrug 3 targeting hypoxic tumor tissue are described. Aromatic nitro group was used as the bio-reductive trigger. Generation of paclitaxel occurred after reduction via a subsequent mechanism of ＂cyclization-cyclization-extrusion＂. The prodrug was stable in PBS （pH = 7.4） and released paclitaxel after chemical reduction of the nitro fimctionality. In aerobic cytotoxicity assays, it exhibited diminished cytotoxicity and is a candidate for further biological evaluation.

摘要：〔目的〕表达重组牛朊病毒正常蛋白特异性片段。〔方法〕用所设计引物以聚合酶链式反应扩增出牛朊病毒正常蛋白特异性片段基因,利用DNA重组技术,将牛朊病毒正常蛋白特异性片段基因插入表达载体pET30a,在大肠杆菌BL21(DE3)中表达,将表达产物(包涵体)用8mol/L尿素溶解,在变性条件下用Cu2+氧化复性纯化。〔结果〕重组表达质粒在大肠杆菌中得到了高效表达,目的蛋白分子量约为15KD,Westernblotting分析表明,目的蛋白具有朊病毒蛋白的抗原特性,变性条件下用Cu2+氧化复性纯化得到电泳纯的重组蛋白。〔结论〕这一工作为下一步制备抗体和进行结构、功能的研究打下扎实基础。