N-Terminus pQE Vector Set
For high-level expression of N-terminally His-tagged proteins
This set provides 5 vectors (pQE-9, pQE-30, pQE-31, pQE-32, and pQE-40) for expression of N-terminally His-tagged proteins. pQE-30, pQE-31, and pQE-32 provide the multiple cloning site (MCS) in all three reading frames while pQE-9 has an alternative, shorter multiple cloning site. pQE-40 is designed for expression of DHFR-fusion proteins and is recommended for expression of poorly expressed proteins or short peptides, which are often prone to proteolysis, as DHFR enhances both stability and antigenicity. Since DHFR itself displays little immunogenicity in mouse and rat, DHFR-fusion proteins are ideal for epitope screening.
QIAexpress pQE vectors combine a powerful phage T5 promoter, which is recognized by E. coli RNA polymerase, with a double lac operator repression module to provide tightly regulated, high-level expression of recombinant proteins in E. coli (see figure QIAExpress pQE Vector). Protein synthesis is effectively blocked in the presence of high levels of lac repressor and the stability of cytotoxic constructs is enhanced. The pQE vectors (see figure pQE Vectors) enable placement of the His tag at either the N- or C-terminus of the recombinant protein.
Inserts encoding proteins of interest are cloned into appropriate constructs (For detailed information see the QIAexpressionist Handbook) and transformed into a suitable E. coli strain for expression. Expression is induced by addition of IPTG. Vector pQE-TriSystem constructs can be transformed into E. coli, used as a shuttle vector for recombinant protein expression in insect cells, or transfected into mammalian cells.
The QIAexpress Expression system provides high-level expression of proteins suitable for
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