Purification of proteins using peptide-ELP based affinity precipitation

Area of Science:

• Biotechnology
• Protein Chemistry
• Biochemistry

Background:

• Traditional protein purification often involves multiple steps and affinity tags.
• Developing efficient, tag-free purification methods is crucial for biotechnology and biopharmaceutical industries.

Purpose of the Study:

• To establish a proof-of-concept for single-step, tag-free protein purification using peptide-elastin-like polypeptide (ELP) fusions.
• To evaluate the impact of varying peptide-protein binding strengths on purification efficacy.

Main Methods:

• Constructing peptide-ELP fusion proteins expressed in E. coli.
• Utilizing ELP's temperature-triggered phase transition for purification.
• Characterizing peptide-protein binding affinities using fluorescence spectroscopy.
• Assessing purification performance through affinity capture, precipitation, and recovery experiments.

Main Results:

• Two out of three tested peptide-ELP systems successfully achieved single-step, tag-free protein purification.
• Peptide-protein binding affinity significantly influenced protein capture efficiency and required molar ratios.
• For intermediate affinity systems, N-terminal dimeric peptide-ELP constructs enhanced purity and yield via avidity effects.

Conclusions:

• Peptide-ELP fusions offer a viable strategy for efficient, tag-free protein purification.
• Optimizing peptide-protein affinity and utilizing avidity effects are key for successful affinity precipitation.
• This approach provides a foundation for developing scalable purification processes for biologics.