Real-Time Affinity Measurements of Proteins Synthesized in Cell-Free Lysate Using Fluorescence Correlation...

Area of Science:

• Biochemistry
• Molecular Biology
• Biophysics

Background:

• High-throughput screening of biomolecular interactions is crucial in medicine and bioscience.
• Traditional methods for protein affinity screening are time-consuming and expensive, requiring cell-based expression, purification, and titration.

Purpose of the Study:

• To develop a rapid, simplified method for assessing protein expression and binding characteristics.
• To enable high-throughput screening of protein-protein interactions without the need for protein purification.

Main Methods:

• Utilized cell-free protein synthesis to produce proteins of interest in the presence of binding partners.
• Employed fluorescence correlation spectroscopy (FCS) to simultaneously measure protein concentration and binding.
• Demonstrated the method in a microcapsule format for ultrahigh-throughput screening.

Main Results:

• Quantified dissociation constants (K_D) in the high picomolar to low nanomolar range for green fluorescent protein (GFP) and an anti-GFP antibody.
• Successfully measured protein expression and binding characteristics in a single "one-pot" reaction within hours.
• Showcased the method's potential for screening thousands of proteins in situ.

Conclusions:

• The developed method offers a fast, cost-effective, and efficient approach for biomolecular interaction analysis.
• This platform facilitates the production and in situ affinity screening of a large number of proteins.
• The technique has broad applications in drug discovery, diagnostics, and fundamental bioscience research.