Engineering a recyclable elastin-like polypeptide capturing scaffold for non-chromatographic protein purification.

Area of Science:

• Biochemistry
• Molecular Biology
• Biotechnology

Background:

• Non-chromatographic protein purification methods offer advantages in speed and cost.
• Previous elastin-like polypeptide (ELP) and dockerin/cohesin-based systems were limited by irreversible binding, preventing scaffold reuse.
• High binding affinity between dockerin and cohesin domains hindered complete dissociation and recycling of the ELP-cohesin scaffold.

Purpose of the Study:

• To develop a recyclable non-chromatographic protein purification method.
• To reduce protein purification costs by enabling the reuse of the ELP-ELP-cohesin capturing scaffold.
• To investigate the efficacy of a modified dockerin tag for reversible protein binding.

Main Methods:

• A truncated dockerin domain with partially impaired calcium-coordinating function was engineered as an affinity tag.
• Target proteins were purified from cell extracts using a single binding step to the ELP-cohesin scaffold.
• EDTA-mediated dissociation was employed to release the bound dockerin-intein tag from the ELP-cohesin scaffold.
• The regenerated ELP-cohesin scaffold was reused for subsequent purification cycles.

Main Results:

• The truncated dockerin domain effectively functioned as an affinity tag for protein purification.
• Efficient dissociation of the bound dockerin-intein tag was achieved using EDTA.
• The regenerated ELP-cohesin scaffold demonstrated no loss in purification efficiency after multiple cycles.
• The method enabled fast, cost-effective, and recyclable protein purification.

Conclusions:

• A recyclable non-chromatographic affinity purification method was successfully developed.
• The use of a modified dockerin tag and EDTA-mediated dissociation allows for scaffold reuse.
• This approach offers a significant advancement in efficient and cost-effective protein purification strategies.