Unveiling Sticholysin II and plasmid DNA interaction: Implications for developing non-viral vectors.

Area of Science:

• Biochemistry
• Biophysics
• Gene Therapy

Background:

• Non-viral gene delivery systems are promising for gene therapy but face challenges with endosomal escape.
• Sticholysin II (StII), a pore-forming protein, can permeabilize membranes and is explored for enhancing delivery systems.

Purpose of the Study:

• To investigate the interaction between Sticholysin II (StII) and plasmid DNA (pDNA).
• To assess the potential of StII-pDNA complexes for improved gene delivery vectors with enhanced endosomal escape.

Main Methods:

• Electrophoretic mobility shift assay (EMSA) to confirm StII-pDNA complex formation.
• Computational predictions to identify interaction interfaces.
• Atomic force microscopy (AFM) and dynamic light scattering (DLS) to characterize complex morphology and size.

Main Results:

• EMSA confirmed StII-pDNA complex formation.
• Computational analysis revealed electrostatic interactions and hydrogen bonds at the interface.
• AFM showed nodular fiber and toroid shapes; DLS indicated micrometer-sized complexes.
• Complexes maintained a net negative charge and StII retained its pore-forming capacity.

Conclusions:

• StII-pDNA complexes show potential for gene delivery, maintaining StII's membrane-permeabilizing ability.
• The negative charge of complexes allows for additional component association for pDNA compaction.
• Further research is needed to regulate StII activity and minimize cytotoxicity for therapeutic applications.