Intrinsically Disordered Ku Protein-Derived Cell-Penetrating Peptides

Area of Science:

• Biochemistry
• Molecular Biology
• Biotechnology

Background:

• Efficient intracellular delivery of bioactive molecules remains a significant challenge in biomedical research.
• Cell-penetrating peptides (CPPs) are recognized as effective carriers for enhancing cellular uptake.
• DNA-binding Ku proteins offer a potential source for novel CPP development due to their structural properties.

Purpose of the Study:

• To develop and characterize novel cell-penetrating peptides (CPPs) derived from the tail extensions of DNA-binding Ku proteins.
• To evaluate the biocompatibility, internalization efficacy, and DNA condensation capabilities of these novel CPPs.
• To assess the potential of these CPPs for delivering plasmid DNA into cells for therapeutic applications.

Main Methods:

• Peptide synthesis and purification.
• Biophysical characterization including assessment of intrinsically disordered state and proline residue importance.
• DNA binding and polyplex formation studies.
• Cellular uptake and intracellular delivery assays using plasmid DNA.

Main Results:

• Novel CPPs were successfully derived from Ku protein tail extensions.
• The lead CPP, Ku-P4, demonstrated high biocompatibility and cellular internalization efficacy.
• The proline residue was identified as critical for maintaining the peptide's disordered state and biocompatibility.
• Effective DNA condensation and polyplex formation were observed, facilitating cell membrane penetration and plasmid DNA delivery.

Conclusions:

• Novel CPPs derived from Ku proteins represent a promising platform for efficient intracellular delivery.
• Ku-P4 exhibits excellent biocompatibility and internalization properties, making it a strong candidate for drug and gene delivery.
• These CPPs have significant potential to improve the efficacy of peptide-drug conjugates and gene therapies.