Rainbow tags: a visual tag system for recombinant protein expression and purification

Area of Science:

• Biochemistry
• Molecular Biology
• Protein Engineering

Background:

• Protein visualization and tracking are crucial in biological research but lack standard methods for protein purification.
• Existing methods for monitoring protein expression and purification are often indirect or require specialized equipment.

Purpose of the Study:

• To develop novel visual tags for real-time monitoring of protein folding and purification.
• To create a colorimetric method for quantifying protein concentration during purification processes.

Main Methods:

• Engineered red and yellow visual tags using heme-binding domain of mosquito cytochrome b5 and FMN-binding domain of human P450 reductase.
• Tested the visual tags with glutathione-S-transferase (GST) to assess their effectiveness in identifying folded protein and tracking during purification.
• Utilized the absorbance signatures of the colored tags for direct protein quantification.

Main Results:

• The developed visual tags effectively identify correctly folded proteins and facilitate tracking throughout expression and purification.
• The tags provide characteristic absorbance signatures enabling direct colorimetric quantification of protein concentrations.
• Demonstrated the integration of colorimetric detection with protein purification processes.

Conclusions:

• Rainbow Tagging provides simple and effective visual tools for protein expression and purification.
• This technology streamlines downstream processing of recombinant proteins.
• Facilitates the development of automated, high-throughput protein expression systems.