BL21-Gold大腸桿菌表達宿主菌及感受態細胞

BioVector NTCC質粒載體菌種細胞蛋白抗體基因保藏中心

BL21-Gold-derived expressionstrains are ideal for performing protein expression studies that utilize the T7RNA polymerase promoter to direct high-level expression. Derived from Escherichiacoli B, these expression strains naturally lack the Lon protease, which candegrade recombinant proteins. In addition, these strains are engineered to bedeficient for a second protease, the OmpT protein. These BL21-Gold-derivedexpression strains incorporate major improvements over the original BL21strain. The BL21-Gold strains feature the Hte phenotype present in the highestefficiency Agilent competent cell strain, XL10-Gold.4 The presence of the Htephenotype increases the transformation efficiency of the BL21-Gold cells to>1 × 108 cfu/μg of pUC18 DNA. In addition, the gene that encodesendonuclease I (endA), which rapidly degrades plasmid DNA isolated by mostminiprep procedures, is inactivated. These two improvements allow directcloning of many protein expression constructs. All three of theBL21-Gold-derived expression strains are resistant to tetracycline. Inaddition, the BL21-Gold(DE3)pLysS strain is resistant to chloramphenicol.

BL21-Gold(DE3) is anall-purpose strain for high-level protein expression and easy induction. TheBL21- Gold(DE3)pLysS strain provides tighter control of protein expression forexpression of toxic proteins. When used with the CE6 bacteriophage, theBL21-Gold cells provide the tightest control of protein expression. Table Iillustrates the features of the BL21-Gold expression strains for proteinexpression.

Genotype

E. coli B F–ompT hsdS(rB– mB–) dcm+ Tetr gal endA Hte