An expression vector tailored for large-scale, high-throughput purification of recombinant proteins

Area of Science:

• Biochemistry
• Molecular Biology
• Protein Chemistry

Background:

• Efficient protein purification is crucial for structural and functional studies.
• Traditional dual-tag systems, like His(6)-tag-maltose-binding protein (MBP), can complicate purification and solubility.
• Issues include incomplete tag removal and loss of protein solubility post-cleavage.

Purpose of the Study:

• To develop an improved purification pipeline for producing milligram quantities of proteins.
• To address the limitations of standard dual-tag systems in protein solubility and purification.
• To create a vector system that facilitates efficient separation of target proteins from fusion tags.

Main Methods:

• Engineered a novel vector producing fusion proteins with MBP, His(6)-tag, and target protein separated by specific protease cleavage sites.
• Utilized co-expressed protease for in vivo cleavage at the first site, generating untagged MBP and His(6)-tagged target protein.
• Employed conventional purification protocols for separating proteins and removing tags.

Main Results:

• The new vector design successfully alleviated issues with protein solubility and tag removal.
• Proteins not truly solubilized by MBP precipitated and were easily separated.
• Untagged MBP was efficiently removed from His(6)-tagged target proteins using standard methods.
• The second cleavage site allowed for complete removal of the His(6)-tag.

Conclusions:

• The engineered vector system provides a more robust and efficient pipeline for protein purification.
• This approach enhances the yield and purity of target proteins for downstream applications.
• The strategy simplifies the process, reducing the need for extensive screening and additional purification steps.