Efficient protein selection based on ribosome display system with purified components.

Area of Science:

• Molecular Biology
• Synthetic Biology
• Biotechnology

Background:

• Ribosome display is a powerful in vitro protein evolution technique.
• The Protein synthesis Using Recombinant Elements (PURE) system offers a cell-free gene expression platform.
• Optimizing ribosome display for efficiency and reproducibility is crucial for protein selection.

Purpose of the Study:

• To develop and optimize an efficient ribosome display method using the PURE system.
• To demonstrate the formation of stable mRNA/ribosome/polypeptide ternary complexes.
• To achieve high-fold enrichment of functional proteins, such as single-chain antibodies (scFv).

Main Methods:

• Utilized the PURE system, comprising purified Escherichia coli gene expression factors and enzymes.
• Performed detailed analyses and optimization of the ribosome display protocol.
• Assessed the formation of stable mRNA/ribosome/polypeptide ternary complexes and mRNA recovery rates.

Main Results:

• Achieved a dramatic increase in mRNA recovery rate due to stable ternary complex formation.
• Demonstrated a 12,000-fold enrichment of single-chain antibody (scFv) cDNA in a single selection round.
• Successfully selected scFv mRNA from a 1:10(10) dilution in competitor mRNA within three rounds.

Conclusions:

• The PURE system provides a reliable and reproducible foundation for ribosome display.
• Optimized ribosome display using the PURE system enables efficient selection of functional proteins.
• This approach significantly enhances the capabilities of in vitro protein evolution techniques.