The soluble fusion proteins cbd - lt 27 in cytoplasm and periplasm of e . coli were purified with cbind 100 resin , the purity of fusion protein was more than 80 % in eluted solution 采用cbind100resin从破菌上清中快速纯化可溶的融合蛋白cbd - l7a27 ，洗脱下来的融合蛋白纯度可达80以上。
2.
The purified enzyme had a specific activity of 68 . 6 u / mg protein . overproduction of pga was often limited by translocation and / or periplasmic processing steps , subsequently resulted in intracellular accumulation of various types of pga precursors and then formed inclusion bodies in the cytoplasm and / or periplasm 经deae - sepharosecl6b离子交换层析和butyl - sepharosecl4b疏水层析，即可得纯度提高20倍、比活为68 . 6u mg的青霉素g酰化酶，两步纯化的总得率达91 。
3.
The supernatant fraction and the precipitation fractions were analyzed by western blotfor strain dh5 a / pkkfpga , 5 - 10 % pga precursors formed as inclusion bodies in the cytoplasm while no inclusion bodies formed in the periplasm , this suggested most pga precursors were transported to the periplasm and matured to active pga and indicated that the maturation of pga in strain dh5 / pkkfpga was limited by the translocation step Western印迹分析表明对于菌株dh5 pkkfpga ， 5 - 10的原前体青霉g素酰化酶在胞内形成了包涵体，说明其成熟的限速步骤在胞内的运输阶段，而菌株dh5 psmlfpga则无明显包涵体形成，说明菌株dh5 psmlfpga改善了青霉素g酰化酶的合成流，因而其表达能力高于菌株dh5 pkkfpga 。
4.
The expressed fusion protein occupied more than 20 % of total bacterial protein . the fusion protein induced mainly existed in the insoluble inclusion body of the cell , only little parts of fusion protein expressed in the cytoplasm , excreted into periplasm and secreted into the cultural medium as soluble protein . through ultrasonic treatment at low temperature , soluble expressed fusion protein could be obtained from the supernatant of lysed cell 表达产物在细胞内外的精细定位研究表明，融合蛋白cbd - lt 27在经诱导的大肠杆菌中表达量占总菌体蛋白的20以上，融合蛋白主要以不溶性包涵体的形式存在于细胞中，少量以可溶产物的形式存在于细胞质、分泌于细胞周质间腔及培养基中。
