Qiagen, 32915, N-Terminus pQE Vector Set

25 µg each: pQE-9, pQE-30, pQE-31, pQE-32, pQE-40

Features

- pQE-30 vectors with MCS in all three reading frames for fast cloning
- pQE-40 vector for poorly expressed proteins, short peptides
- pQE-40 vector expresses DHFR-fusions, enhancing stability and antigenicity

Product Details

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.

Principle

Element: Description
Optimized promoter/operator element: Consists of the phage T5 promoter and two lac operator sequences, which increase the probability of lac repressor binding and ensure efficient repression of the powerful T5 promoter
Synthetic ribosomal binding site RBSII: For efficient translation
6xHis-tag coding sequence: Either 5' or 3' to the polylinker cloning region
Translational stop codons: In all reading frames for convenient preparation of expression constructs
Two strong transcriptional terminators: t 0 from phage lambda, and T1 from rrnB operon of E. coli , to prevent read-through transcription and ensure stability of the expression construct
ColE1 origin of replication: From pBR322
Beta-lactamase gene ( bla ): Confers ampicillin resistance

Procedure

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.

Applications

- Purification of functional, conformationally active proteins
- Purification under denaturing conditions for antibody production
- Crystallization for determination of three-dimensional structure
- Assays involving protein–protein and protein–DNA interactions

The QIA express Expression system provides high-level expression of proteins suitable for many applications, including: