Novel biotinylated plasmid expression vectors retain biological function and can bind streptavidin

Area of Science:

• Molecular Biology
• Biotechnology
• Gene Delivery

Background:

• Plasmid vectors are crucial for gene expression and delivery.
• Efficient protein-plasmid conjugation is needed for advanced biotechnological applications.
• Current methods may compromise plasmid function or transfection efficiency.

Purpose of the Study:

• To develop a method for covalently attaching proteins to plasmid expression vectors.
• To assess the impact of biotinylation and streptavidin binding on plasmid activity.
• To investigate the gene expression enhancement using large hybrid biotinylated plasmids.

Main Methods:

• Covalent attachment of biotin to a chloramphenicol acetyltransferase (CAT) gene-containing plasmid.
• Electrophoretic mobility shift assay to confirm streptavidin binding.
• Transfection of biotinylated plasmids into mouse fibroblasts and CAT activity assays.
• Construction of large hybrid plasmids by re-ligating digested biotinylated and unbiotinylated plasmids.
• Calcium phosphate precipitation for transfection and slot-blot analysis for DNA quantification.

Main Results:

• Biotinylated plasmids retained 40% of native biological activity after streptavidin binding.
• Hybrid biotinylated plasmids showed a 25-fold increase in CAT expression compared to original biotinylated plasmids.
• Enhanced expression was not due to increased transfection efficiency.
• Receptor-mediated delivery was not demonstrated with the tested system.

Conclusions:

• Protein conjugation to plasmid vectors via biotinylation is feasible while maintaining biological function.
• Large hybrid biotinylated plasmid structures significantly enhance gene expression.
• This method offers a promising strategy for improving gene delivery and expression systems.