Self-Assembled Peptide-Based System for Mitochondrial-Targeted Gene Delivery: Functional and Structural Insights

Area of Science:

• Biotechnology and Molecular Medicine
• Mitochondrial Biology and Disease

Background:

• Human mitochondrial dysfunction causes severe, incurable diseases.
• Effective gene carriers for mitochondrial DNA delivery are currently unavailable.
• Targeted gene delivery to mitochondria is a promising therapeutic strategy.

Purpose of the Study:

• To develop a novel dual-domain peptide for selective mitochondrial DNA delivery.
• To characterize the physicochemical properties and biological efficiency of the peptide/DNA complexes.
• To establish a reliable tool for studying mitochondrial gene transfection.

Main Methods:

• Rational design of dual-domain peptides incorporating DNA-condensing, cell-penetrating, endosome-disruptive, and mitochondria-targeting sequences.
• Analysis of peptide secondary structures and physicochemical properties (stability, size, ζ potential) of peptide/DNA complexes.
• Optimization of formulation through qualitative and quantitative studies, confirmed by nuclear magnetic resonance (NMR) spectroscopy.

Main Results:

• An optimized peptide formulation successfully transfected 82 ± 2% of mitochondria in a human cell line with high biocompatibility.
• NMR studies confirmed the bipartite peptide design with segregated helical (mitochondrial import) and unstructured (DNA interaction) domains.
• Lysine-specific interactions were found to be crucial for peptide-DNA self-organization and complex structural arrangement, enhancing biological efficiency.

Conclusions:

• The developed dual-domain peptide vector is effective for mitochondria-specific DNA delivery.
• This novel gene vector represents a reliable tool for investigating mitochondrial transfection and its therapeutic potential.
• The findings pave the way for new therapeutic strategies for mitochondrial disorders.