大肠杆菌RNA聚合酶σ亚基基因的表达及表达产物的分离纯化

EXPRESSION OF SIGMA SUBUNIT GENE OF Escherichia coli RNA POLYMERASE,ISOLATION AND PURIFICATION OF ITS EXPRESSION PRODUCT

将2种表达质拉pEGMD（含rpoD基因）和pETF（含rpoS基因）转化到BL21（DE3）菌株中，培养菌体。破碎细胞，用盐酸抓溶解包含体，经DEAE－纤维素柱层析，SDS－PAGE检测可得纯化σ的蛋白。通过紫外分光光度法测定蛋白浓度，实验表明σ38蛋白的得率为菌体温重的0．27％，σ70蛋白的得率为菌体湿重的0．06％。

Two kinds of pledd pEGMD (containal rpo D gene) and pETF (contained rpo S gene) were transformed into BL21 (DE3) strain and cultural. The cells were ruptured and the content was dissolved with guanidine chloride. Purified σ protrin was obtained after treaing with DEAE-cellulose chromatography, and measured with SDS-PAGE. Cpncentration of the protein was measured by ultraviolet spectrophotomter. The harvest of σ38 was 0. 27% of the fresh cdi weight, and σ70 was 0. 06%.