诱导重组人生长激素工程菌高效表达的研究

Study on inducing high-level expression of recombinant human growth hormone

目的 筛选诱导重组人生长激素 (rhGH)工程菌高效表达的最佳条件 ,为中试及工业化发酵培养提供依据。方法 质粒PBV GH转化 4种不同宿主菌 ,比较 6种不同培养基在不同pH值、氧含量改变情况下 ,rhGH工程菌的生长和表达差异 ,筛选并确定最适宿主菌、最佳培养基及最佳诱导表达条件。结果 ①E coliDH5α为最适宿主菌 ;②TB培养基为最佳培养基 ;③培养基pH7 5～ 7 8有利于目的蛋白的表达。④在半对数生长期 (培养 4～ 5h)迅速升温 ,且菌密度控制在D6 0 0nm3 0之前诱导可获得较高的重组蛋白表达量 ,rhGH表达量占菌体总蛋白的 40 %。发酵时间为 1 0h。结论 E coliDH5α为rhGH高效表达的最适工程菌 ,E coliDH5α/PBV GH在pH7 5～ 7 8的TB培养基中发酵生长 1 0h,可使菌量最佳扩增 。

Objective To establish a sound fermentation process of preparing recombinant human growth hormone (rhGH) for the basis of pilot and industrial production. Methods Different conditions including different host cells transferred plasmid PBV GH, culture mediums, the values of pH and concentrations of O 2 were compared to obtain the best inducing expression condition of rhGH. Results The expression of rhGH kept in a higher level of about 40% of total bacterial proteins when E.coli DH5α as host cell, TB cultivating medium, pH 7.5-7.8, bacterial density of D 600 3.0, rapidly increased temperature in log time,and a fermentaion time of 10 h were employed. Conclusion The high level expression of rhGH can be achieved in E.coli DH5α with TB medium at pH value from 7.5 to 7.8 for 10 h fermentation.