One-step affinity isolation of recombinant protein using the baculovirus/insect cell expression system

Area of Science:

• Molecular Biology
• Biotechnology
• Protein Expression

Background:

• Traditional recombinant protein expression often faces challenges with solubility and post-translational modifications.
• Prokaryotic systems may struggle with producing large or complex eukaryotic proteins.

Purpose of the Study:

• To develop a novel method for single-step affinity isolation of recombinant proteins expressed in insect cells.
• To create versatile baculovirus transfer vectors for simplified protein purification and enhanced expression.

Main Methods:

• Development of two baculovirus transfer vectors enabling fusion protein expression with glutathione-S-transferase (GST).
• Utilizing glutathione affinity chromatography for single-step enrichment of GST-fusion proteins from insect cell lysates.
• Employing an engineered thrombin cleavage site for removal of the GST tag post-purification.

Main Results:

• Successful isolation of various recombinant proteins, including GST, human low-density lipoprotein receptor, and cystic fibrosis transmembrane conductance regulator (CFTR) domains and full-length protein.
• Demonstrated increased solubility and higher affinity yields of recombinant fusion proteins in insect cells compared to prokaryotic systems.
• Achieved enrichment of recombinant proteins constituting less than 5% of total insect cell protein.

Conclusions:

• The developed baculovirus transfer vectors provide a general and efficient method for eukaryotic protein synthesis and isolation.
• This approach offers advantages such as eukaryotic post-translational modification, improved protein solubility, and suitability for large/complex polypeptides.
• The single-step affinity isolation technique simplifies purification and enhances the yield of recombinant proteins for diverse research applications.